CJEU, 4th chamber, April 10, 2014, No C-247/11 P

THE COURT (Fourth Chamber),

Judgment

1 By their appeals, Areva SA ('Areva'), Alstom SA ('Alstom'), T & D Holding SA, Alstom Grid SAS and Alstom Grid AG (the latter four companies, together, 'the Alstom group companies', and all five companies, together, 'the appellant companies') seek to have set aside the judgment of the General Court of the European Union in Joined Cases T-117-07 and T-121-07 Areva and Others v Commission [2011] ECR II-633 ('the judgment under appeal'), in so far as, by that judgment, that court rejected their actions for annulment in part of Commission Decision C(2006) 6762 final of 24 January 2007 relating to a proceeding under Article [81 EC] and Article 53 of the EEA Agreement (Case COMP-F-38.899 - Gas insulated switchgear), a summary of which was published in the Official Journal of the European Union (OJ 2008 C 5, p. 7) ('the contested decision'), or, in the alternative, a reduction in the amount of the fine imposed on the appellant companies by that decision.

I - Legal context

2 Article 23 of Council Regulation (EC) No 1-2003 of 16 December 2002 on the implementation of the rules on competition laid down in Articles 81 [EC] and 82 [EC] (OJ 2003 L 1, p. 1), entitled 'Fines', provides as follows:

'...

2 The Commission may by decision impose fines on undertakings and associations of undertakings where, either intentionally or negligently:

(a) they infringe Article 81 [EC] or Article 82 [EC] ...

...

3. In fixing the amount of the fine, regard shall be had both to the gravity and to the duration of the infringement.

...'

3 Article 31 of that regulation, entitled 'Review by the Court of Justice', is worded as follows:

'The Court of Justice shall have unlimited jurisdiction to review decisions whereby the Commission has fixed a fine or periodic penalty payment. It may cancel, reduce or increase the fine or periodic penalty payment imposed.'

II - Background to the dispute and the contested decision

4 The facts of the dispute, as set out in paragraphs 1 to 35 of the judgment under appeal, may be summarised as follows.

5 The disputes concern a cartel relating to the sale of gas insulated switchgear ('GIS'), which is used to control energy flow in electricity grids. It is heavy electrical equipment, used as a major component for turnkey power substations.

6 At paragraphs 6 to 9 of the judgment under appeal, the various companies involved in that dispute are described as follows:

'6 Alstom (formerly Alsthom), a limited liability company under French law, is the parent company of a group of companies ("the Alstom Group"). Throughout the period from 15 April 1988 to 8 January 2004, the Alstom Group was active in the electricity transmission and distribution sector ("the T & D sector") and, in particular, in GIS.

7 The Alstom Group's GIS activities in France were carried out by Alsthom SA (France) until 1989, when Alsthom SA (France) was renamed GEC Alsthom SA, which was a whollyowned subsidiary of GEC Alsthom NV. On 16 November 1992, Kléber Eylau SA was created and was granted the French GIS activities by an agreement which took effect on 7 December 1992. GEC Alsthom SA owned 99.76% of Kléber Eylau and Etoile Kléber owned 0.04%. In June 1993 Kléber Eylau's name was changed to GEC Alsthom T & D SA, which, in June 1998, became Alstom T & D SA. Alstom T & D SA was a whollyowned subsidiary of Alstom Holdings (France), which was in turn a whollyowned subsidiary of Alstom.

8 From January 1986, Alstom's GIS activities in Switzerland ran parallel to those in France, when Sprecher Energie AG became a whollyowned subsidiary of Alsthom. In November 1993, Sprecher Energie became GEC Alsthom T & D AG, which, in July 1997, became GEC Alsthom AG and, in June 1998, became Alstom AG ("Alstom Switzerland"). On 22 December 2000, the latter was acquired by Alstom Power (Schweiz) AG. The new entity was called Alstom (Schweiz) AG. In November 2002, a new legal entity was created within the Alstom Group, to which the activities in the T & D sector in Switzerland were transferred. Initially named Alstom (Schweiz) Services AG, that new entity was subsequently renamed Alstom T & D AG.

9 All of the Alstom Group's T & D sector activities were transferred, on 8 January 2009, to a group of which Areva, a limited liability company under French law with a management board and a supervisory board, is the parent company ("the Areva Group"). From 9 January to 11 May 2004, the Areva group's GIS activities were carried out by Areva T & D SA and by Areva T & D AG, whollyowned subsidiaries of Areva T & D Holding SA ["Areva T & D Holding"], which is itself whollyowned by Areva (taken as a whole, "the companies of the Areva Group").'

7 On 3 March 2004, ABB Ltd ('ABB') informed the Commission of the existence of a cartel in the GIS sector and submitted an oral application for immunity from fines pursuant to the Commission Notice on immunity from fines and reduction of fines in cartel cases (OJ 2002 C 45, p. 3) ('the Leniency Notice'). On 25 April 2004, the Commission granted ABB conditional immunity.

8 On the basis of statements made by ABB, the Commission launched an investigation and, on 11 and 12 May 2004, carried out on-the-spot inspections, inter alia at the premises of Areva T & D SA. On 20 April 2006, the Commission adopted a statement of objections which, in addition to being addressed to Alstom and the Areva Group companies, was also addressed to ABB, Fuji Electric Holdings Co. Ltd and Fuji Electric Systems Co. Ltd, Hitachi Ltd and Hitachi Europe Ltd, Japan AE Power Systems Corp., Mitsubishi Electric System Corp., Nuova Magrini Galilieo SpA, Schneider Electric SA, Siemens AG, Toshiba Corp. and five other companies - the parent company of which was VA Technologie AG - including VA Technologie AG itself.

9 On 24 January 2007, the Commission adopted the contested decision and the 20 companies to which the statement of objections had been addressed were notified of the decision.

10 At paragraphs 29 to 31 of the judgment under appeal, the characteristics of the cartel at issue, as presented in the contested decision, were summarised as follows:

'29 In recitals 113 to 123 of the contested decision, the Commission stated that the various undertakings which participated in the cartel had coordinated the allocation of GIS projects worldwide - except for specific markets - according to agreed rules in order to maintain quotas largely reflecting estimated historic market shares. It pointed out that the allocation of GIS projects had been carried out on the basis of a joint "Japanese" quota and a joint "European" quota, which the Japanese and European producers then had to distribute amongst themselves. An agreement signed in Vienna [Austria] on 15 April 1988 ("the GQ Agreement") established rules allowing the allocation of GIS projects to either Japanese producers or to European producers and to set their value against the corresponding quota. In addition, in recitals 124 to 132 of the contested decision, the Commission stated that the various undertakings which participated in the cartel had entered into an unwritten agreement ..., under which GIS projects in Japan, on the one hand, and in the countries of European members of the cartel, on the other - together described as the "home countries" for GIS projects - were reserved to Japanese members and European members of the cartel respectively. GIS projects located in the "home countries" were not the subject of information exchanges between the two groups and were not charged to their respective quotas.

30 The GQ Agreement also contained rules relating to the exchange of information necessary for operation of the cartel between the two groups of producers, carried out in particular by their respective secretaries, and to the manipulation of the bidding procedures concerned and the fixing of prices for GIS projects which could not be allocated. Under the terms of Annex 2 to the GQ Agreement, it applied across the world, except in the United States, Canada, Japan and 17 Western European countries. Furthermore, under the [unwritten agreement], GIS projects in European countries other than the "home countries" were also reserved for the European group, as the Japanese producers had undertaken not to submit bids for GIS projects in Europe.

31 According to the Commission, the sharing of GIS projects among European producers was governed by an agreement also signed in Vienna on 15 April 1988, entitled "E-Group Operation Agreement for GQ Agreement" ... It indicated that the distribution of GIS projects in Europe followed the same rules and procedures as those governing the distribution of GIS projects in other countries. In particular, GIS projects in Europe also had to be notified, recorded, allocated, arranged or have received a minimum price.'

11 On the basis of the findings of fact and legal assessments set out in the contested decision, the Commission concluded that the undertakings involved had infringed Article 81 EC and Article 53 of the Agreement on the European Economic Area of 2 May 1992 (OJ 1994 L 1, p. 3) ('the EEA Agreement') and imposed on them fines calculated in accordance with the methods set out in the Guidelines on the method of setting fines imposed pursuant to Article 15(2) of Regulation No 17 and Article 65(5) of the ECSC Treaty (OJ 1998 C 9, p. 3) ('the Guidelines') and in the Leniency Notice.

12 The Commission decided that, pursuant to the leniency notice, it was required to grant ABB's application for immunity, but that the leniency applications submitted by other companies, including Areva, had to be rejected.

13 Articles 1 and 2 of the contested decision provide as follows:

'Article 1

The following undertakings infringed Article [81 EC ]... and Article 53 [of the EEA Agreement] by participating, during the periods indicated, in a complex of agreements and concerted practices in the [GIS] sector in the [European Economic Area] (EEA):

... ...

(b) [Alstom], from 15 April 1988 to 8 January 2004;

(c) [Areva], from 9 January 2004 to 11 May 2004;

(d) Areva T & D AG, from 22 December 2003 to 11 May 2004;

(e) Areva T & D Holding ..., from 9 January 2004 to 11 May 2004;

(f) Areva T & D SA, from 7 December 1992 to 11 May 2004;

...

Article 2

For the infringements referred to in Article 1, the following fines are imposed:

...

(b) [Alstom]: EUR 11 475 000;

(c) [Alstom], jointly and severally with Areva T & D SA: EUR 53 550 000. On the amount imposed on Areva T & D SA (EUR 53 550 000), Areva ..., Areva T & D Holding ... and Areva T & D AG, jointly and severally with Areva T & D SA: EUR 25 500 000;

...'

14 It is apparent from the information provided by the appellant companies that, on 7 June 2010, Areva sold its entire business in the T & D sector. In particular, Alstom re-acquired the transmission activities. Subsequently, Areva T & D Holding took the name T & D Holding SA, Areva T & D SA became Alstom Grid SAS and Areva T & D AG is now known as Alstom Grid AG.

III - The actions before the General Court and the judgment under appeal

15 It is apparent from paragraph 50 of the judgment under appeal that, in support of their applications for annulment, the Areva group companies relied on seven pleas in law, which the General Court summarised as follows:

'The first plea alleges breach of the duty to state reasons laid down in Article 253 EC. The second plea is based, in essence, on infringement of the rules on attributing liability for infringements of Article 81(1) EC and Article 53(1) of the EEA Agreement and breach of the general principles of legal certainty and nonretroactivity. The third plea alleges, in essence, infringement of the rules on attributing liability for infringements of Article 81(1) EC and Article 53(1) of the EEA Agreement. The fourth plea is based, in essence, on infringement of the rules on attributing liability for infringements and on joint and several liability for the payment of fines resulting from Article 81(1) EC and Article 53(1) of the EEA Agreement, infringement of Article 7 EC and breach of the general principles of equal treatment, proportionality, legal certainty, nonretroactivity of legal penalties and effective judicial protection. The fifth plea alleges infringement of the rules on joint and several liability for the payment of fines resulting from Article 81(1) EC and Article 53(1) of the EEA Agreement. The sixth plea alleges, in essence, infringement of Article 23(2)(a) of [Regulation No 1-2003] and of Section 2 of [the Guidelines], an error of assessment and breach of the general principles of equal treatment and proportionality. Lastly, the seventh plea is based, in essence, on an error of assessment and infringement of Article 81 EC and Article 53(1) of the EEA Agreement, and of the Leniency Notice.'

16 At paragraph 51 of the judgment under appeal, the General Court summarised the eight pleas in law put forward by Alstom in support of the form of order sought by it as follows:

'The first plea alleges infringement of the right to an effective remedy. The second plea is based, in essence, on infringement of the rules on joint and several liability for the payment of fines resulting from Article 81 EC and Article 53 of the EEA Agreement, on breach of the general principle of legal certainty and the general principle that the penalty must be specific to the offender and to the offence and on breach of the duty to state reasons. The third plea alleges an infringement of the duty to state reasons, as required under Article 253 EC. The fourth plea is based, principally, on infringement of the rules on attributing liability for infringements of Article 81 EC and Article 53 of the EEA Agreement and on an error in law or, in the alternative, on an infringement of Article 25 of Regulation No 1-2003. The fifth plea is based, in essence, on an error of assessment, infringement of the Guidelines, breach of the principles of equal treatment and proportionality and of the duty to state reasons. The sixth plea alleges, in essence, infringement of the rules on proving the continuous nature of the infringement resulting from Article 23(3) of Regulation No 1-2003 and Article 15(2) of Council Regulation No 17 of 6 February 1962, First regulation implementing Articles [81 EC] and [82 EC], as amended (OJ 1962 English Special Edition Series I, p. 87), and breach of the principle of legal certainty. The seventh plea is based on a failure to observe the rights of the defence and infringement of Article 27(1) of Regulation No 1-2003. The eighth plea is based, in essence, on infringement of the Guidelines and, in the alternative, on breach of the principle of proportionality.'

17 At paragraph 317 of the judgment under appeal, the General Court upheld the applicants' pleas alleging breach of the principles of proportionality and equal treatment and decided to annul Article 2(b) and (c) of the contested decision, in so far as it increased the basic amount of the fine imposed on Alstom and the Areva Group companies by 50% - an increase identical to that imposed on Siemens AG - on account of the aggravating circumstance of playing the role of leader in the infringement.

18 In the exercise of its unlimited jurisdiction, at paragraph 323 of the judgment under appeal, the General Court set the rate of increase for the basic amount of the fine to be paid by Alstom and Areva T & D SA on account of that aggravating circumstance at 35% and that for the fine to be paid by Areva T & D AG, Areva and Areva T & D Holding at 20%, thereby varying the fines imposed in Article 2(b) and (c) of the contested decision.

19 The General Court dismissed all the other pleas relied on by Alstom and the Areva group companies.

20 Accordingly, at paragraph 2 of the operative part of the judgment under appeal, the General Court annulled Article 2(b) and (c) of the contested decision and, at paragraph 3 of the operative part, set the fines to be paid as follows:

'- Alstom ...: EUR 10 327 500;

- Alstom ...: EUR 48 195 000, jointly and severally with Areva T & D SA, EUR 20 400 000 of the amount owed by Areva T & D SA being payable jointly and severally by Areva T & D AG, Areva ... and Areva T & D Holding ...'

IV - Forms of order sought by the parties and the procedure before the Court of Justice

21 By its appeal, Areva claims that the Court should:

- set aside the judgment under appeal;

- if the Court considers that the state of the proceedings is such as to permit final judgment to be given in the matter, annul Articles 1(c) and 2(c) of the contested decision; in the alternative, substantially reduce the amount of the fine imposed on Areva; order the Commission to pay all the costs, including those incurred by it before the General Court;

- if the Court considers that the state of the proceedings is not such as to permit final judgment to be given in the matter, refer the case back to a Chamber of the General Court with a different composition and reserve the costs.

22 By their appeal, the Alstom group companies claim that the Court should:

- set aside the judgment under appeal;

- if the Court considers that the state of the proceedings is such as to permit final judgment to be given in the matter, annul Article 1(b), (d), (e) and (f) and Article 2(b) and (c) of the contested decision; in the alternative, substantially reduce the amount of the fines imposed on them; order the Commission to pay the costs, including those relating to the proceedings before the General Court;

- if the Court considers that the state of the proceedings is not such as to permit final judgment to be given in the matter, refer the case back to a Chamber of the General Court with a different composition and reserve the costs.

23 By order of the President of the Court of 20 July 2011, Cases C-247-11 P and C-253-11 P were joined for the purposes of the written and oral procedure and judgment.

V - The appeals

A - Summary of the grounds of appeal

24 Areva raises four grounds for annulment in support of its appeal. The first ground, which is divided into three parts, alleges infringement by the General Court of its obligation to provide adequate reasoning, and failure to observe the rights of the defence in its examination as to whether Areva actually exercised decisive influence over Areva T & D SA and Areva T & D AG during the period from 9 January to 11 May 2004, in so far as the General Court:

- substituted its own reasoning for that of the Commission by adding to the contested decision, a posteriori, grounds to substantiate its finding that the Commission was entitled to conclude that it had not rebutted the presumption of actual exercise of decisive influence;

- formulated arguments from which it is not possible to ascertain the reasons why it did not uphold its arguments in rebuttal of that presumption; and

- imposed an impossible burden of proof on it ('probatio diabolica') as regards the rebuttal of that presumption and refused to grant it the opportunity to express its views on the new grounds added to the contested decision.

25 The three other grounds relied on by Areva allege infringement of, respectively:

- the rules on joint and several liability for payment of fines, and consequent breach of the principle of legal certainty and the principle that penalties must be specific to the offender and the offence, in so far as the General Court failed to censure the Commission for concluding that Areva and Alstom were de facto jointly and severally liable - two companies which have never formed, together, a common economic unit;

- the rules on delegation of the Commission's powers, the obligation the General Court is under to provide adequate reasoning and the principle that penalties must be specific to the offender and the offence, in so far as the General Court failed to censure the Commission for not addressing, in the contested decision, the issue of Alstom's and Areva's respective contributions to the fine and, thus, by implication, delegating the resolution of that issue to the national court or to an arbitration panel, whereas such a decision falls within the Commission's discretionary powers to impose penalties and cannot be delegated; and

- the principles of proportionality and equal treatment, in so far as the General Court approved the fine imposed jointly and severally on Areva for an infringement lasting four months, the amount of that fine representing approximately half the fine Alstom is required to pay, jointly and severally, for an infringement lasting 12 years, or twice the amount of the fine that Alstom is required to pay alone for its direct participation in the infringement at issue for a period of four years, without there being any justification on the basis of a significant difference in the size of the companies or the gravity of the infringement during the period at issue.

26 The Alstom group companies raise five grounds of annulment in support of their appeal, some of which are divided into a number of parts, alleging, respectively, infringement of:

- the obligation to provide adequate reasoning, in so far as the General Court found, first, that the Commission had stated to the requisite legal standard the reasons for its conclusion that it accepted that Alstom was jointly and severally liable with Areva T & D SA and Areva T & D AG, on the basis of the fact that Alstom had failed to rebut the presumption that it exercised decisive influence over its subsidiaries, whereas the Commission did not address the evidence put forward by Alstom to rebut that presumption (first part) and, second, that the Commission was not under any obligation to state the reasons why two companies that did not form an economic entity on the date on which a decision was adopted could be given a fine for the payment of which they were jointly and severally liable (second part);

- the obligation the General Court is under to provide adequate reasoning, in so far as it:

- substituted its own reasoning for that of the Commission by adding to the contested decision, a posteriori, grounds not found in that decision (first three parts), and

- failed to address to the requisite legal standard the appellant's argument that two companies that do not form an economic unit on the date on which the Commission decision was adopted could not be given a fine for which they are jointly and severally liable (fourth part);

- Article 101 TFEU and the principles of the right to a fair hearing and the presumption of innocence, enshrined in Articles 47 and 48 of the Charter of Fundamental Rights of the European Union and guaranteed by Article 6 of the European Convention for the Protection of Human Rights and Fundamental Freedoms, signed in Rome on 4 November 1950, in so far as the General Court:

- in its application of the presumption of exercise of decisive influence, used a definition of the exercise of such influence by a parent company over its subsidiary which was totally unrelated to any actual conduct on the market in question, thus rendering that presumption irrebuttable; and

- erred in law in the determination of Areva T & D Holding's actual exercise of decisive influence over Areva T & D SA and Areva T & D AG during the period from 9 January to 11 May 2004;

- the concept of joint and several liability, in so far as the General Court:

- held that the concept of joint and several liability determines the respective shares to be contributed by the companies held jointly and severally liable for payment of a fine;

- failed to censure the Commission for delegating its power to determine the liability of each of the undertakings penalised, thereby infringing the principle of legal certainty and the principle that the penalty must be specific to the offender and the offence, as well as Article 13 TEU;

- the obligation the General Court is under to respond to the pleas raised, in so far as it misrepresented the scope of the plea alleging breach of the right to an effective legal remedy and judicial protection and, as a consequence, did not respond to the plea put forward but to another plea which had not been raised.

B - Examination of the grounds

1. The grounds relating to whether the unlawful conduct of the subsidiaries may be imputed to their parent companies

a) The first ground relied on by the Alstom group companies, alleging breach of the obligation the Commission is under to provide adequate reasoning

i) The first part of the first ground of appeal relied on by the Alstom group companies

- Arguments of the parties

27 By the first part of their first ground of appeal, which relates to paragraphs 90 to 99 of the judgment under appeal, the Alstom group companies claim that the General Court failed to censure the Commission for failing to have regard to the obligation it is under to provide adequate reasoning. In particular, the Commission did not respond to the arguments raised by Alstom at paragraphs 90 to 150 of its response to the statement of objections, which were supported by documents annexed to that response whose purpose was to rebut the presumption of actual exercise of decisive influence. That evidence showed that, notwithstanding the presumption that Alstom exercised decisive influence over its wholly-owned subsidiaries, at the time of the infringement the conduct of those subsidiaries on the market was totally independent of their parent company.

28 The Alstom group companies also maintain that the General Court distorted the contested decision, in particular at paragraph 95 of the judgment under appeal, because recitals 345 to 347 to the decision do not summarise paragraphs 90 to 150 of the reply to the statement of objections.

29 The Commission submits that the Alstom group companies' arguments should be rejected.

- Findings of the Court

30 It should be noted, at the outset, that infringement of the competition rules by a subsidiary may be imputed to the parent company in particular where, although having separate legal personality, that subsidiary does not decide independently upon its own conduct on the market but carries out, in all material respects, the instructions given to it by the parent company, having regard in particular to the economic, organisational and legal links between those two legal entities (see, inter alia, Case C-97-08 P Akzo Nobel and Others v Commission [2009] ECR I-8237, paragraph 58, and Joined Cases C-628-10 P and C-14-11 P Alliance One International and Standard Commercial Tobacco v Commission and Commission v Alliance One International and Others [2012] ECR, paragraph 43).

31 In such a situation, since the parent company and its subsidiary form a single economic unit and therefore form a single undertaking for the purposes of Article 81 EC, the Commission may address a decision imposing fines to the parent company without having to establish the personal involvement of the latter in the infringement (see Akzo Nobel and Others v Commission, paragraph 59, Alliance One International and Standard Commercial Tobacco v Commission and Commission v Alliance One International and Others, paragraph 44).

32 The Court has made it clear that, in the particular case of a parent company with a 100% shareholding in a subsidiary which has infringed the European Union's competition rules, that parent company is able to exercise decisive influence over the conduct of its subsidiary, and there is a rebuttable presumption that the parent company does in fact exercise such influence (see Alliance One International and Standard Commercial Tobacco v Commission and Commission v Alliance One International and Others, paragraph 46 and the case-law cited).

33 In those circumstances, it is sufficient for the Commission to prove that the entire share capital of a subsidiary is held by its parent in order for it to be presumed that the parent exercises decisive influence over the commercial policy of that subsidiary. The Commission will then be able to regard the parent company as jointly and severally liable for payment of the fine imposed on its subsidiary, unless the parent company, which has the burden of rebutting that presumption, adduces sufficient evidence to show that its subsidiary acts independently on the market (Akzo Nobel and Others v Commission, paragraph 61, and Alliance One International and Standard Commercial Tobacco v Commission and Commission v Alliance One International and Others, paragraph 47).

34 Moreover, where a decision concerning the application of European Union competition rules affects several addressees and relates to the attribution of liability for the infringement, the decision must contain an adequate statement of reasons with respect to each of the addressees, in particular those who, according to that decision, must bear the liability for the infringement. Accordingly, with regard to a parent company held responsible for the unlawful conduct of its subsidiary, such a decision must, as a general rule, contain a statement of reasons capable of justifying the attribution of liability for that infringement to the parent company (Alliance One International and Standard Commercial Tobacco v Commission and Commission v Alliance One International and Others, paragraph 75).

35 As regards, in particular, a Commission decision which relies exclusively, with respect to certain addressees, on the presumption that they actually exercised decisive influence, the Commission is in any event required - if it is not to render that presumption in reality irrebuttable - to explain adequately to those addressees the reasons why the elements of fact and of law put forward did not suffice to rebut that presumption (Case C-521-09 P Elf Aquitaine v Commission [2011] ECR I-8947, paragraph 153).

36 However, the Commission is not in any way bound to rely exclusively on that presumption. There is nothing to prevent the Commission from establishing that a parent company actually exercises decisive influence over its subsidiary by means of other evidence or by a combination of such evidence and that presumption (Alliance One International and Standard Commercial Tobacco v Commission and Commission v Alliance One International and Others, paragraph 49).

37 In the present case, as observed by the General Court at paragraph 91 of the judgment under appeal, it is clear from the contested decision, in particular recitals 335, 348 to 356 and 358, that in order to determine whether Alstom was liable for the infringements committed by its wholly-owned subsidiaries, the Commission did not ultimately rely exclusively on the presumption that it did actually exercise decisive influence, but instead based its decision on the 'dual basis' method, combining that presumption with other evidence, namely other factual evidence produced during the administrative procedure which supported that presumption (see, by analogy, Alliance One International and Standard Commercial Tobacco v Commission and Commission v Alliance One International and Others, paragraph 50).

38 As the Advocate General observed at points 25 and 26 of his Opinion, it is clear, in the light of those explicit considerations in the contested decision, that the Commission cannot be criticised for not having supplied detailed reasoning, in accordance with the requirements of the case-law, with respect to the attribution to Alstom of liability for the infringement in question.

39 Such reasoning meets the objective pursued by the obligation to state the reasons on which an individual decision is based, which is, in addition to enabling judicial review to be carried out, to give the person concerned sufficient information to enable it to ascertain whether the decision may be vitiated by a defect making it possible to challenge its validity (see, by analogy, Case C-508-11 P ENI v Commission [2013] ECR, paragraph 71).

40 With regard in particular to the evidence adduced by Alstom at paragraphs 90 to 150 of its response to the statement of objections to rebut the presumption that it actually exercised decisive influence, while it would appear that the Commission did not, in the contested decision, address each of those items of evidence individually, it nevertheless gave the person concerned sufficient information to enable it to ascertain whether that decision was well founded or whether it was vitiated by a defect making it possible to challenge its validity and to enable the General Court to review its legality (see, to that effect, inter alia, Joined Cases C-189-02 P, C-202-02 P, C-205-02 P to C-208-02 P and C-213-02 P Dansk Rørindustri and Others v Commission [2005] ECR I-5425, paragraph 462, and ENI v Commission, paragraph 72).

41 As the Advocate General observed at point 28 of his Opinion, it is clear that, in its detailed statement of reasons as to why liability was to be imputed to Alstom for the infringement in question, according to the 'dual basis' method, as set out in the contested decision, the Commission carried out, inter alia, a global assessment of the arguments put forward by Alstom at paragraphs 90 to 150 of its response to the statement of objections, in so far as those arguments were relevant for the purpose of rebutting the presumption that Alstom actually exercised decisive influence.

42 With regard to a decision such as the contested decision, which, as already noted at paragraph 37 above, bases its determination whether an infringement committed by a subsidiary may be imputed to the parent company on a 'dual basis' method, combining the presumption that the parent company actually exercised decisive influence with evidence set out in detail in that decision, such a global assessment is, in principle, commensurate with the degree of reasoning required on the part of the Commission, since it enables the parent company to be apprised of the reasons why the Commission has decided to impute liability to it for the infringement committed by its subsidiary.

43 Moreover, the Alstom group companies have not explained how the purportedly flawed reasons given for the contested decision prevented them from properly defending their rights before the General Court or prevented that court from exercising its power of review. On the contrary, the detailed examination carried out by the General Court, at paragraphs 93 to 97 of the judgment under appeal, of the arguments put forward by Alstom in order to rebut the presumption of decisive influence demonstrates, rather, that Alstom was able properly to defend its rights before the General Court and that that court was able to exercise its power to review that decision (see, by analogy, Orders of 7 February 2012 in Case C-421-11 P Total and Elf Aquitaine v Commission, paragraph 57, and of 13 September 2012 in Case C-495-11 P Total and Elf Aquitaine v Commission, paragraph 50).

44 Moreover, it should be noted, first of all, as regards the standard of reasoning required, that, unlike the situation which gave rise to the judgment in Case C-521-09 P Elf Aquitaine v Commission [2011] ECR I-8947, relied on by the Alstom group companies, those companies were not, in the present case, faced with the first Commission decision in which the Commission altered its usual approach and relied solely on the presumption that the parent company had exercised decisive influence over the subsidiary in order to impute the infringement to the parent company (see, by analogy, Order in Case C-421-11 P Elf Aquitaine v Commission, paragraph 58).

45 Lastly, contrary to the contentions of the Alstom group companies and as is apparent from paragraph 97 of the judgment under appeal, there was nothing to preclude the Commission from relying in its examination as to whether the infringement committed by its subsidiaries could be imputed to Alstom, inter alia, on evidence provided by third parties, namely by the Areva group companies.

46 It follows that the first part of the first ground of appeal relied on by the Alstom group companies must be rejected.

ii) The second part of the Alstom group companies' first ground of appeal

47 By the second part of their first ground of appeal, which concerns paragraph 200 of the judgment under appeal, the Alstom group companies take issue with the General Court for failing to criticise the Commission for not giving specific reasons for the fact that it made Alstom and Areva T & D SA jointly and severally liable for payment of a fine even though they no longer formed an undertaking at the time of adoption of the contested decision.

48 The second part of the first ground of appeal must be rejected.

49 It is established case-law that if the unlawful conduct of a subsidiary can be imputed to its parent company, those companies may be regarded, during the period of the infringement, as forming a single economic unit and thus a single undertaking within the meaning of the competition law of the European Union. In those circumstances, the Commission will be entitled to hold the parent company liable for the unlawful conduct of its subsidiary during that period and, as a consequence, for payment of the fine imposed on the subsidiary (see, to that effect, inter alia, Alliance One International and Standard Commercial Tobacco v Commission and Commission v Alliance One International and Others, paragraphs 44 and 47 and the case-law cited).

50 In the light of that well established principle, the General Court was correct to find, at paragraph 200 of the judgment under appeal, that, by the contested decision, the Commission was entitled to take the view that the fact that, at the time when the Commission's decision establishing the infringement was adopted, the subsidiary which had committed the infringement and the parent company to which the infringement could be imputed were no longer part of the same economic entity or, therefore, a single undertaking within the meaning of Article 81 EC, cannot in itself alone prevent the Commission from using its power to impose a fine to be paid jointly and severally by those companies, so that specific reasons do not need to be given in relation to that point.

51 In those circumstances, since it is apparent from the examination of the first part of the first ground of appeal relied on by the Alstom group companies that reasons were stated to the requisite legal standard in the contested decision, in so far as Alstom was apprised of the reasons which led the Commission to impute to it the unlawful conduct of its subsidiaries and the General Court was able to exercise its powers of review, the General Court cannot be criticised for not taking issue with the Commission for failing to give specific reasons concerning the imposition of a fine to be paid jointly and severally by those companies, which no longer formed a single undertaking.

52 That is the case, a fortiori, where, as observed in essence by the Advocate General at points 39 and 40 of his Opinion, the imposition of such a fine on companies no longer forming part of the same undertaking at the time when the Commission's decision is adopted cannot be distinguished from the Commission's previous practice, so that the reasoning required may be less specific.

53 It follows that the second part of the Alstom group companies' first ground of appeal and, accordingly, its first ground of appeal in its entirety, must be rejected.

b) The first ground of appeal relied on by Areva and the second ground of appeal raised by the Alstom group companies, alleging infringement of the obligation the General Court is under to provide adequate reasoning

54 It should be noted, first, that it has consistently been held that the statement of the reasons on which a judgment of the General Court is based must clearly and unequivocally disclose that court's reasoning in such a way as to enable the persons concerned to ascertain the reasons for the decision taken and the Court of Justice to exercise its power of review (see, inter alia, ENI v Commission, paragraph 74).

55 However, the obligation to state reasons does not require the General Court to provide an account which responds exhaustively and one by one all to the arguments put forward by the parties to the case. The reasoning may therefore be implicit, on condition that it enables the persons concerned to know why the General Court has not upheld their arguments and provides the Court of Justice with sufficient material for it to exercise its power of review (see, inter alia, Case C-439-11 P Ziegler v Commission [2013] ECR, paragraph 82).

56 Moreover, in reviewing the legality of acts under Article 263 TFEU, the Court of Justice and the General Court cannot under any circumstances substitute their own reasoning for that of the author of the contested act (see, inter alia, Case C-73-11 P Frucona Košice v Commission [2013] ECR, paragraph 89 and the caselaw cited).

57 However, the General Court cannot be criticised for substituting its own reasoning for that of the Commission, with regard to the question whether an infringement committed by a subsidiary may be imputed to the parent company, if the grounds of the judgment in question refer to evidence relied on by the applicants before the General Court to rebut the presumption of actual exercise of decisive influence, which the General Court is required to examine in its review of the legality of the decision at issue (see, to that effect, Case C-421-11 Total and Elf Aquitaine v Commission, paragraph 65, and Case C-495-11 Total and Elf Aquitaine v Commission, paragraph 60).

i) The first part of the second ground of appeal relied on by the Alstom group companies

58 By the first part of their second ground of appeal, the Alstom group companies claim that, at paragraphs 102 to 110 of the judgment under appeal, the General Court substituted its own reasoning for that of the Commission. In those paragraphs, the General Court examined the evidence put forward by Alstom at paragraphs 90 to 150 of its response to the statement of objections to rebut the presumption that it actually exercised decisive influence, with regard to the period from 7 December 1992 to 8 January 2004. However, it is alleged that the contested decision does not contain any assessment of that evidence, so that the General Court in effect added such an assessment to the grounds of that decision.

59 That argument is based on the premiss that, in the contested decision, the Commission did not duly consider the evidence set out by Alstom at paragraphs 90 to 150 of its response to the statement of objections.

60 However, as is apparent from the examination of the Alstom group companies' first ground of appeal, that premiss cannot be accepted, since it was established at paragraph 42 above that the contested decision sets out adequate reasons as to whether the infringement committed by its subsidiaries may be imputed to Alstom, including a global approach to the evidence relied on by Alstom at paragraphs 90 to 150 of its response to the statement of objections.

61 Moreover, as is clear from paragraph 57 above, the General Court cannot be criticised for giving a more detailed account, at paragraphs 102 to 110 of the judgment under appeal, of the reasoning in the contested decision relating to paragraphs 90 to 150 of Alstom's response to the statement of objections, since, in those paragraphs of the judgment under appeal, the General Court simply examined in greater detail the arguments and evidence submitted by Alstom during the administrative procedure.

62 It follows that the first part of the Alstom group companies' second ground of appeal must be rejected.

ii) The first ground of appeal raised by Areva and the second part of the second ground of appeal relied on by the Alstom group companies

- Arguments of the parties

63 By its first ground of appeal, which relates to paragraphs 144 to 152 of the judgment under appeal, Areva takes issue with the General Court for failing to have regard to the obligation it is under to provide adequate reasoning and to the rights of the defence.

64 First of all, at paragraph 150 of the judgment under appeal, the General Court substituted its own reasoning for that of the Commission by adding to the contested decision two new factors in order to enable it to reject the claims that, for the period from 9 January to 11 May 2004, Areva and Areva T & D holding SA did not have sufficient experience of the T & D sector to be able actually to exercise decisive influence over the conduct of Areva T & D SA and Areva T & D AG (together, 'the T & D subsidiaries').

65 Those new factors consist in the assertion that the possibility cannot be ruled out that Areva and Areva T & D Holding could have acquired knowledge of the T & D sector during the period between the conclusion of the agreement for the sale of Alstom's T & D subsidiaries in September 2003 and the actual transfer of those subsidiaries on 8 January 2004, and the assertion that it could not be ruled out either that the recruitment of a new director for those subsidiaries from outside the group enabled Areva to equip itself with expertise in that sector.

66 Next, it is claimed that it is not possible, on the basis of the considerations set out by the General Court, to understand its reasons for not upholding the arguments put forward by Areva. Accordingly, the judgment under appeal is vitiated by defective reasoning.

67 Lastly, it is claimed the General Court also infringed Areva's rights of defence. By relying on factors which in reality were assumptions or hypothetical, the General Court made the presumption of actual exercise of decisive influence irrebuttable and imposed a probatio diabolica on Areva in so far as concerns its endeavours to demonstrate that it did not in fact exercise decisive influence over its T & D subsidiaries, by requiring it to adduce negative proof of its noninterference with their conduct. The General Court did not give Areva the opportunity to comment on those two new factors added to the contested decision.

68 By the second part of their second ground of appeal, the Alstom group companies claim that the General Court failed to have regard to its obligation to provide adequate reasoning, relying on essentially the same argument as that put forward by Areva in its first ground of appeal.

69 The Commission disputes those arguments. In particular, it contends that the ground relied on by Areva is inadmissible since, by that plea, Areva is in reality criticising the General Court's assessment of the evidence.

- Findings of the Court

70 The Court rejects, first of all, as inadmissible the argument raised by Areva for the first time at the reply stage, by which it takes issue with the General Court for failing to censure the Commission for infringing its obligation to state reasons in its analysis of whether Areva actually exercised decisive influence over its T & D subsidiaries.

71 That argument is fundamentally different from the arguments put forward by Areva in its appeal, which concern only the obligation the General Court is under to provide adequate reasoning.

72 That argument constitutes, in accordance with the rule laid down in Articles 127 and 190 of the Rules of Procedure, a new plea in law introduced in the course of proceedings, which must be rejected as inadmissible, since it is not based on matters of law or of fact which came to light in the course of the procedure before the Court of Justice (see, inter alia, the judgment of 19 December 2013 in Joined Cases C-239-11 P, C-489-11 P and C-498-11 P Siemens and Others v Commission, paragraph 371 and the case-law cited).

73 Second, it is appropriate to examine, in the light of the case-law cited at paragraphs 54 to 57 above, the argument put forward by Areva and the Alstom group companies that, at paragraph 150 of the judgment under appeal, the General Court added two new factors to the reasoning of the contested decision, which are referred to at paragraph 64 above.

74 It is necessary to examine paragraph 150 of the judgment under appeal, in the context of the General Court's reasoning at paragraphs 144 to 152 of that judgment in response to the third plea in law relied on, by which the Areva group companies argued before the General Court that the parent companies Areva and Areva T & D Holding did not have sufficient experience of the T & D sector to be able actually to exercise decisive influence over the conduct of its T & D subsidiaries.

75 As the Advocate General also observed, in essence, at points 65 to 71 of his Opinion, that examination discloses that the General Court did not, at paragraph 150 of the judgment under appeal, add two new factors to the reasoning of the contested decision, substituting its own reasoning for that in that decision, but simply answered in detail, in the context of its review of the legality of that decision, the arguments raised before it to rebut the presumption of actual exercise of decisive influence, on the basis that the infringement in question could not be imputed to the parent companies Areva and Areva T&D Holding as they did not have sufficient experience of the T & D sector.

76 Third, the Court rejects Areva's argument that the General Court's reasoning concerning the two alleged new factors added to the contested decision does not enable it to understand how those factors might justify the finding that it actually exercised decisive influence.

77 It is sufficient in that regard to point out that, as is apparent from paragraph 75 above, the finding of actual exercise of decisive influence is not based on the two factors referred to by Areva, which simply constitute arguments formulated by the General Court in response to claims made by the Areva group companies in the administrative procedure, and subsequently before the General Court, that the parent companies of that group were not in fact able to exercise decisive influence over the subsidiaries concerned because they lacked experience of the T & D sector.

78 Fourth, Areva's argument alleging infringement of the rights of defence, in so far as it was not given the opportunity to comment on those two alleged new factors, must be rejected. The rights of defence could not have been infringed, since it is apparent from paragraph 75 above that those factors were raised by the General Court in response to arguments advanced by the Areva group companies themselves.

79 Fifth, the Court also rejects as unfounded Areva's argument that the rights of defence were infringed in so far as the General Court imposed a probatio diabolica on it, which consisted in requiring it to adduce negative proof of its noninterference with the conduct of its subsidiaries.

80 The approach adopted by the General Court to the evidence put forward by the Areva group companies to rebut the presumption of actual exercise of decisive influence does not, taken as a whole, amount to the imposition of a probatio diabolica. It follows from caselaw that it is for entities seeking to rebut that presumption to adduce any evidence relating to the economic, organisational and legal links between the subsidiary in question and its parent company which, in their view, is capable of showing that those two companies did not constitute a single economic entity (Elf Aquitaine v Commission, paragraph 65).

81 The fact that it is difficult to adduce the evidence necessary to rebut a presumption does not in itself mean that that presumption is in fact irrebuttable, especially where the entities against which the presumption operates are those best placed to seek that evidence within their own sphere of activity (Elf Aquitaine v Commission, paragraph 70).

82 In the light of all the foregoing, the first ground of appeal relied on by Areva and the second part of the Alstom group companies' second ground of appeal must be rejected.

iii) The fourth part of the second ground of appeal relied on by the Alstom group companies

83 By the fourth part of their second ground of appeal, the Alstom group companies contend that the General Court vitiated the judgment under appeal by a twofold failure to state reasons, in so far as it is not possible, on the basis of paragraph 206 of that judgment, to ascertain why, first, the Commission was able, without stating reasons in the contested decision in that regard, to impose fines on legal entities which no longer constituted an economic unit at the time of adoption of the decision and, second, why the case-law which those companies cited was not relevant.

84 In view of the considerations set out at paragraphs 49 and 50 above, it is sufficient to note that the General Court did not err in law in finding, at paragraph 200 of the judgment under appeal, that the Commission could not be criticised for not having stated specific reasons for imposing a fine, to be paid jointly and severally, on Alstom and Areva T & D SA, having due regard to the fact that those companies no longer formed a single economic entity at the date on which the contested decision was adopted and, at paragraph 206 of that judgment, that it does not follow from the caselaw that only those companies which formed an economic unit at the date when the decision imposing the fine was adopted can have a fine imposed on them for which they are jointly and severally liable.

85 Accordingly, the fourth part of the second ground of appeal relied on by the Alston group companies must be rejected.

86 It follows that Areva's first ground of appeal and the second ground of appeal relied on by the Alston group companies, with the exception of the third part of the latter ground, which will be considered in due course, must be rejected.

c) The Alstom group companies' third ground of appeal, alleging infringement of Article 101 TFEU, in particular the rules governing the imputation of infringements, the principles of the right to a fair hearing and the presumption of innocence

i) The first part of the Alstom group companies' third ground of appeal

87 By the first part of their third ground of appeal, the Alstom group companies take issue with the General Court for having used, in its application of the presumption of exercise of decisive influence at paragraphs 84 to 110 of the judgment under appeal, a definition of the exercise by a parent company of decisive influence over its subsidiary that does not in any way reflect actual conduct on the market in question, and for having therefore rendered that presumption irrebuttable.

88 The Alstom group companies maintain, in particular, that, by inferring the actual exercise of decisive influence from the mere existence of organisational, economic and legal links between the parent company and one of its subsidiaries and not from specific facts linked to particular actual conduct on the relevant market, the General Court exceeded the limits of what is reasonable by imposing a probatio diabolica on Alstom, since that company could rebut the presumption that it actually exercised decisive influence only by denying the existence of those links and, accordingly, its own existence.

89 In that regard, it should be noted, first, that, contrary to the contentions of the Alstom group companies, the General Court did not infer the actual exercise of decisive influence from the mere existence of organisational, economic and legal links between the parent company and one of its subsidiaries.

90 The General Court found, at paragraph 103 of the judgment under appeal, that the documents produced by Alstom during the administrative procedure prove that the management of the Alstom Group, under the responsibility of Alstom, were involved in defining the course of action on the market in relation to the Alstom Group's T & D division and its various branches of activity, and that it permanently supervised compliance with that course of action by that division and its different branches of activity.

91 Next, as the Commission correctly submitted, in a situation in which the presumption of actual exercise of decisive influence may be applicable, by its inclusion, if appropriate, in a dual base method, as used in the present case, it cannot be required to demonstrate that the parent company actually used the organisational, economic and legal links that characterise its relationship with its subsidiaries by reference to specific facts linked to particular actual conduct on the relevant market, as such a requirement would render that presumption ineffective.

92 Furthermore, as is apparent from paragraphs 80 and 81 above, it cannot be claimed that the General Court actually applied an irrebuttable version of that presumption by imposing on Alstom a probatio diabolica with regard to the evidence adduced by Alsom to rebut that presumption.

93 Finally, with regard to whether the presumption of actual exercise of decisive influence is compatible with the principles of the right to a fair hearing and the presumption of innocence, the Court has already held that that presumption is proportionate to the aim pursued and, therefore, remains within acceptable limits, since it is intended, in particular, to strike a balance between, on the one hand, the importance of the objective of combatting conduct contrary to the competition rules, in particular to Article 81 EC, and of preventing a repetition of such conduct and, on the other hand, the requirements flowing from certain general principles of European Union law, such as the principle of the presumption of innocence, the principle that penalties should be applied solely to the offender and the principle of legal certainty, as well as the rights of the defence, including the principle of equality of arms. It is for that reason in particular that the presumption is rebuttable (see, to that effect, ENI v Commission, paragraph 50, and Case C-501-11 P Schindler Holding and Others v Commission [2013], paragraphs 107 and 108).

94 Accordingly, the first part of the Alstom group companies' third ground of appeal must be rejected.

ii) The second part of the Alstom group companies' third ground of appeal

95 By the second part of their third ground of appeal, the Alstom group companies claim that the General Court erred in law by upholding the contested decision, at paragraphs 144 to 152 of the judgment under appeal, in so far as it found that Areva T & D Holding did in fact exercise decisive influence over Areva T & D SA and Areva T & D AG during the period from 9 January to 11 May 2004. To justify the Commission's assessment, the General Court relied, at paragraphs 150 of that judgment, on the two factors already criticised by Areva in the context of its first ground of appeal, which are referred to at paragraph 65 above.

96 It should be noted that the arguments put forward in this context by the Alstom group companies overlap to a large degree with the arguments relied on by Areva in its first ground of appeal in respect of the same paragraphs of the judgment under appeal.

97 Those arguments have already been rejected by the Court, at paragraph 77 above, in the context of the response to Areva's first ground of appeal, from which it is apparent that, when it examined a series of arguments put forward by Areva to rebut the presumption that it actually exercised decisive influence, the General Court analysed the arguments relied on by Areva and expressed the view, in carefully chosen and measured terms, that those factors were not capable of demonstrating that no decisive influence was in fact exercised.

98 As stated at paragraphs 80, 81 and 92 above, in so doing, the General Court did not impose on Alstom a probatio diabolica rendering the presumption of actual exercise of decisive influence irrebuttable.

99 Moreover, in so far as it also contends that the General Court's assessment of those two factors was factually incorrect, without in any way establishing that those factors were distorted, Alstom's argument is inadmissible.

100 It follows that as the second part of the Alstom group companies' third ground of appeal cannot succeed either, the third ground of appeal must be rejected in its entirety.

2. The grounds of appeal relating to the application of the rules governing joint and several liability for payment of fines

101 Areva, in its second and third grounds of appeal, and the Alstom group companies, in the third part of their second ground of appeal and in their fourth ground of appeal, allege a number of errors of law arising from the General Court's interpretation and application of the rules governing joint and several liability for payment of fines imposed by the Commission on different legal entities held jointly and severally liable on the basis of the fact that they form part of the same undertaking which has been found to be responsible for an infringement of the European Union's competition rules.

102 An initial series of arguments thus raised by the appellant companies concerns 'de facto' joint and several liability for payment of the fine imposed by the Commission on Areva and Alstom in their capacity as successive parent companies of subsidiaries that committed infringements of the competition rules, which, those companies claim, the General Court failed to censure, even though it is contrary, in particular, to the principle of legal certainty and the principle that penalties must be specific to the offender and the offence.

103 A second series of arguments, in which the appellant companies allege infringement of those principles, of Article 7 EC and of the obligation to provide adequate reasoning, concerns certain considerations set out in the judgment under appeal relating to how joint and several liability is allocated internally, namely a set of principles outlined by the General Court which govern the determination of the respective shares of the fine to be paid by those held jointly and severally liable from the perspective of their internal relationship, once the fine has been paid in full to the Commission by one or more of those joint and several debtors.

a) The arguments relating to the de facto joint and several liability imposed on the parent companies Areva and Alstom

i) Arguments of the parties

104 The appellant companies contend that the General Court failed to have regard to the principle of legal certainty and the principle that the penalty must be specific to the offender and the offence, in that it did not call into question the Commission's application of the rules governing joint and several liability for payment of fines, since the Commission imposed de facto joint and several liability on Alstom and Areva, two successive parent companies of subsidiaries which committed infringements of the European Union's competition rules, even though those parent companies had never constituted an economic unit between them.

105 Areva adds that the General Court also failed to have regard to those principles by imposing a variation of the fines, in the exercise of its unlimited jurisdiction, thereby also giving rise to de facto joint and several liability.

106 The Alstom group companies submit that that de facto joint and several liability arises, first, from the fact that the sum of EUR 25 500 000, reduced to EUR 20 400 000 by the General Court, imposed jointly and severally on Areva and the T & D subsidiaries, is wholly incorporated in the sum of EUR 53 550 000, reduced to EUR 48 195 000 by the General Court, imposed jointly and severally on Alstom and its former subsidiary Areva T & D SA and, second, the fact that the total of the maximum amounts for which the successive parent companies are held liable exceeds the amount to be paid by the subsidiary.

107 The effect of that 'cascade' method of determination is to establish de facto joint and several liability as between Alstom and Areva, as the amount actually recovered by the Commission from one parent company has a direct bearing on the amount that may by claimed by the Commission from the other parent company, even though those companies have never formed part of the same undertaking for the purpose of the European Union's competition rules. Moreover, such a method does not enable the parent companies in question to be apprised, without any ambiguity, of the exact amount of the fine that each of them is required to pay.

108 In Case T-40-06 Trioplast Industrier v Commission [2010] ECR II-4893, the General Court confirmed, in a context of successive parent companies of subsidiaries that had committed infringements of the competition rules, which was, for all essential purposes, identical to the present cases, that such a method of determining joint and several liability from an external perspective is at odds with the principle that a penalty must be specific to the offender and the offence.

109 The Commission contends that the grounds relied on by the appellant companies are new and, therefore, inadmissible, as they are intended to take issue with the General Court for not having censured the Commission for establishing de facto joint and several liability as between the parent companies Areva and Alstom. They are pleas which the appellant companies omitted to raise during the proceedings at first instance, when they could have done so. The pleas relating to the rules governing joint and several liability raised before the General Court concerned only the actual or 'de jure' joint and several liability as between Areva T & D SA and each of the successive parent companies, Alstom and Areva, as defined in the contested decision.

110 As regards the substance, the Commission submits, in the alternative, that the sale of Areva T & D SA during the infringement period at issue gives rise to dual joint and several liability on the part of that subsidiary with each of its successive parent companies. However, while the method used in the present case to define joint and several liability may entail an overlapping of the amounts that may be claimed from Areva and Alstom, it does not follow from this that those companies will have de jure joint and several liability. Indeed, what matters in law is simply the joint and several liability of each parent company with the transferred subsidiary.

111 Furthermore, where a subsidiary is held jointly and severally liable with successive parent companies, it cannot be contrary to European Union law to calculate the fine payable by those companies on the basis of the full starting amount, which is the same as the starting amount imposed on the subsidiary. Contrary to the appellant companies' contentions, at paragraph 74 of Trioplast Industrier v Commission, the General Court did confirm the lawfulness of that method, which is, moreover, more advantageous for the parent companies in question than other methods which might have been used in such cases.

ii) Findings of the Court

- Admissibility

112 The Commission raises a plea of inadmissibility in respect of the appellant companies' arguments concerning the alleged de facto joint and several liability imposed by the Commission as between the parent companies Areva and Alstom, contending that the appellant companies did not raise such arguments in their application at first instance. At first instance, those companies merely criticised the de jure joint and several liability of Areva T & D SA and each of its successive parent companies. They are, therefore, new pleas, which are inadmissible in an appeal.

113 In accordance with settled case-law, to allow a party to put forward for the first time before the Court of Justice a plea in law which it did not raise before the General Court would in effect allow that party to bring before the Court a wider case than that heard by the General Court. In an appeal, the Court's jurisdiction is, as a general rule, confined to a review of the General Court's assessment of the pleas argued before it (see, inter alia, Alliance One International and Standard Commercial Tobacco v Commission, paragraph 111).

114 However, an argument which was not raised at first instance does not constitute a new plea that is inadmissible at the appeal stage if it is simply an amplification of an argument already developed in the context of a plea set out in the application before the General Court (see, to that effect, inter alia, Siemens and Others v Commission, paragraph 287).

115 As the Advocate General observed, in essence, at points 117 to 120 of his Opinion, it should be noted that, in the second plea of its application at first instance, alleging infringement of the rules governing joint and several liability for payment of fines, deriving from, inter alia, the principle of legal certainty and the principle that the penalty must be specific to the offender and the offence, Alstom put forward an argument specifically criticising the method of determining the fine, which consisted in incorporating the amount of the fine for which Areva was held jointly and severally liable with its former T & D subsidiaries in the fine for which Alstom was held jointly and severally liable with Areva T & D SA.

116 Therefore, whilst Alstom did not expressly raise, at first instance, complaints in respect of the Commission's establishment of 'de facto' joint and several liability, it is clear that it specifically criticised, on the same legal basis as that relied on in the appeal, the method on which such liability was based. Consequently, Alstom's argument alleging de facto joint and several liability does not constitute a new plea, which is inadmissible at the appeal stage, since it is simply the amplification of an argument already developed in the context of a plea raised before the General Court.

117 With regard to Areva, it should be noted that, before the General Court, it raised a plea alleging infringement of the rules governing joint and several liability, deriving from the principle of legal certainty, which overlaps in part with basis of the plea raised in the appeal criticising the alleged de facto joint and several liability. While the plea raised at first instance concerned, as such, only the de jure joint and several liability as between Areva T & D SA and Alstom, the fact nevertheless remains that in that plea Areva raised questions concerning the dual joint and several liability imposed on Areva T & D SA and each of its successive parent companies.

118 Furthermore, as argued by Areva, in exercising its powers of unlimited jurisdiction, the General Court imposed a fine using the 'cascade' method of determination. It follows that the General Court therefore relied on that method, so that the argument alleging de facto joint and several liability deriving from the application of that method has its origins in the judgment under appeal and that the validity of that method may be called into question in the appeal (see, to that effect, Joined Cases C-231-11 P to C-233-11 P Commission v Siemens Österreich and Others and Siemens Transmission & Distribution and Others v Commission [2014] ECR, paragraph 102 and the case-law cited).

119 In those circumstances, the Commission's plea of inadmissibility must be rejected.

- Substance

120 According to case-law, where a number of legal persons may be held personally liable for participation in an infringement of the European Union's competition rules because they form part of a single undertaking responsible for the infringement, the Commission has the power, under Article 23(2) of Regulation No 1-2003 to impose a fine for which those persons are jointly and severally liable (see, to that effect, Commission v Siemens Österreich and Others and Siemens Transmission & Distribution and Others v Commission, paragraphs 39 to 51).

121 However, when it decides to exercise that power to impose penalties, the Commission is not free to determine how joint and several liability is to be imposed from an external perspective or, in particular, the amount of the fine in respect of which it may demand full payment by each of those held jointly and severally liable (see, to that, effect, Commission v Siemens Österreich and Others and Siemens Transmission & Distribution and Others v Commission, paragraphs 52 and 54).

122 As the European Union concept of joint and several liability for payment of a fine is merely the manifestation of an ipso jure legal effect of the concept of an 'undertaking', the determination of the amount of the fine in respect of which the Commission may demand payment in full by each of those held jointly and severally liable derives, in any individual case, from the application of that concept of an undertaking (see, to that effect, Commission v Siemens Österreich and Others and Siemens Transmission & Distribution and Others v Commission, paragraphs 51 and 57).

123 It should be recalled in that regard that the authors of the Treaties chose to use the concept of an undertaking to designate the perpetrator of an infringement of competition law, who is liable to be punished pursuant to Articles 81 EC and 82 EC, not other concepts such as the concept of a company or firm or of a legal person (Commission v Siemens Österreich and Others and Siemens Transmission & Distribution and Others v Commission, paragraphs 42).

124 Moreover, the European Union legislature used that concept of an undertaking in Article 23(2) of Regulation No 1-2003 to define the entity on which the Commission may impose a fine in order to penalise an infringement of the European Union's rules on competition.

125 The Court of Justice has consistently held that, for the purposes of European Union competition law, the concept of an undertaking covers any entity engaged in an economic activity, regardless of the legal status of the entity or the way in which it is financed. That concept must be understood as covering an economic unit, even if, from a legal perspective, that unit is made up of a number of natural or legal persons (see, inter alia, Commission v Siemens Österreich and Others and Siemens Transmission & Distribution and Others v Commission, paragraph 43).

126 Furthermore, in determining joint and several liability from its external perspective, namely the liability imposed by the Commission on the various persons comprising the undertaking who may be required to pay the whole of the fine imposed on the undertaking, the Commission is subject to certain restrictions.

127 Accordingly, the Commission must adhere to the principle that penalties must be specific to the offender and the offence, which requires, in accordance with Article 23(3) of Regulation No 1-2003, that the amount of the fine to be paid jointly and severally must be determined by reference to the gravity of the infringement for which the undertaking concerned is held individually responsible and the duration of the infringement (Commission v Siemens Österreich and Others and Siemens Transmission & Distribution and Others v Commission, paragraph 52).

128 In that context, the Commission must also respect the principle of legal certainty, which requires that any measure adopted by the institutions of the European Union should be clear and precise, so as to enable the persons concerned to ascertain precisely what their rights and obligations are under the measure and take steps accordingly (see, to that effect, inter alia, Joined Cases C-201-09 P and C-216-09 P ArcelorMittal Luxembourg v Commission and Commission v ArcelorMittal Luxembourg and Others [2011] ECR I-2239, paragraph 68).

129 In the present case, while it does not establish, as such, a formal link of joint and several liability between the successive parent companies, Alstom and Areva, it is clear that the method chosen by the Commission and confirmed by the General Court to establish joint and several liability as between Areva T & D SA, as subsidiary, and those parent companies, which consisted in incorporating the amount of the fine for which Areva and the Areva group companies to which that subsidiary belonged were jointly and severally liable, in the fine for which Alstom and that subsidiary were jointly and severally liable, is nevertheless likely in reality to produce the same effects as those arising under such a link.

130 Indeed, the effect of such a determination of joint and several liability from an external perspective may be to require one of the parent companies, first of all, to pay to the Commission all the fines for which the successive parent companies of the subsidiary which committed the infringement of the competition rules are liable, even though the parent companies in question have never been part of a single undertaking for the purpose of European Union competition law. Then, once the whole fine has been paid to the Commission, that parent company will have to seek, if necessary by means of an action for indemnity before a national court, recovery from the other parent company of those fines to the extent of that company's share of liability for payment, thus exposing it to the risk that that other parent company may be insolvent.

131 Such a definition of joint and several liability is at odds with the principle that the penalty must be specific to the offender and the offence, referred to at paragraph 127 above. That definition enables the Commission to require one of the parent companies to pay a fine punishing infringements for which, for another part of the infringement period, an undertaking of which it has never formed part is responsible, namely, in the present case, the undertaking to which the other parent company belongs, not a fine based on the share of joint and several liability attributable to the undertaking of which it formed part at the time the infringement was committed by that undertaking.

132 Moreover, while the joint and several liability mechanism enables the Commission to reduce the risk that one of the companies forming part of the same undertaking will be insolvent, which forms part of the objectives of ensuring that the Commission operates effectively and of deterrence when dealing with infringements of the competition rules (Commission v Siemens Österreich and Others and Siemens Transmission & Distribution and Others v Commission, paragraph 59), that mechanism cannot be used to force one company to bear the risk of the insolvency of another company where those companies have never formed part of the same undertaking.

133 Where the Commission intends to make a subsidiary that has committed an infringement jointly and severally liable with each of the parent companies with which it has, in succession, formed a separate undertaking during the infringement period, that principle requires that institution to fix separately, for each of the undertakings involved, the amount of the fine for which the companies forming part of the undertaking are jointly and severally liable, according to the gravity of the infringement for which each of the undertakings concerned is individually responsible and the duration of that infringement.

134 It is true that it does not follow from the principle that the penalty must be specific to the offender and the offence that, under such a definition of joint and several liability, each company is required to infer from the decision imposing a fine for which it is jointly and severally liable with one or more other companies the share of the fine that it must pay vis-à-vis those other companies, once the Commission has been paid the full amount of the fine (Commission v Siemens Österreich and Others and Siemens Transmission & Distribution and Others v Commission, paragraph 66).

135 On the contrary, that principle requires, with regard to the external determination of joint and several liability, that, in accordance with such a definition of joint and several liability, each successive parent company must be in a position to infer from such a decision its share of liability for payment of the fine, corresponding to the part of the fine imposed on the subsidiary which may be imputed to it and which the Commission may claim from it.

136 It should also be noted that the total sum of the amounts of the fine for which Areva and Alstom were found jointly and severally liable, namely, respectively, EUR 25 500 000, reduced to EUR 20 400 000 by the General Court, and EUR 53 550 000, reduced to EUR 48 195 000 by the General Court, is greater than the amount of the fine imposed jointly and severally on those companies with the subsidiary Areva T & D SA, namely EUR 53 550 000, reduced to EUR 48 195 000 by the General Court.

137 In a situation such as that in the present case, the liability of Areva and Alstom, as parent companies, for the infringement committed is wholly derived from the liability of a subsidiary which belonged to those companies in succession (see, by analogy, Case C-286-11 P Commission v Tomkins [2013] ECR, paragraphs 43 and 49).

138 It follows that the total amount which the parent companies may be required to pay cannot be greater than the amount which that subsidiary must pay.

139 Furthermore, since the determination of joint and several liability, as established in the contested decision and confirmed by the judgment under appeal, does not enable the parent companies in question to ascertain precisely the amount of the fine they are required to pay in respect of the period during which they were held jointly and severally liable, with their subsidiary, for the infringement, the Court also finds that there has been infringement of the principle of legal certainty.

140 That uncertainty cannot be dispelled by the rule of liability in equal measure applicable by default, such as that referred to by the General Court at paragraph 215 of the judgment under appeal, under which, in the absence of any finding in the Commission's decision imposing joint and several liability for payment of a fine on a number of companies that some of the companies in the undertaking have a greater share of responsibility than others for the undertaking's participation in the cartel during a specific period, it must be presumed that they share equal responsibility and, accordingly, must pay an equal share of the fines for which they have been held jointly and severally liable.

141 European Union law does not lay down any such rule (Commission v Siemens Österreich and Others and Siemens Transmission & Distribution and Others v Commission, paragraphs 70 and 71). Moreover, that rule relates, in any event, only to the internal allocation of liability for payment of the fine among those jointly and severally liable, once the fine has been paid to the Commission, not to the determination, from the external perspective, of joint and several liability, of the respective amounts that the Commission may claim from the legal entities that formed part of each of the undertakings which succeeded one another during the infringement period.

142 Lastly, as observed by the Advocate General at point 141 of his Opinion, the Commission's argument that it was entitled to calculate the fine for the subsidiary which committed the infringement and its successive parent companies solely on the basis of the starting amount established for the subsidiary cannot call into question the conclusion that the definition of joint and several liability adopted by the Commission and confirmed by the General Court constitutes an infringement of the principle of legal certainty and the principle that the penalty must be specific to the offender and the offence.

b) The arguments relating to the internal allocation of liability for payment of the fine between those jointly and severally liable

i) Arguments of the parties

143 First, the appellant companies claim that the General Court infringed the principle of legal certainty and the principle that the penalty must be specific to the offender and the offence by finding, at paragraph 215 of the judgment under appeal, that, in the light of the rule of liability in equal measure applicable by default, referred to at paragraph 140 above, each of the penalised companies was in a position to infer from the contested decision the share of the fine for which it was responsible in its internal relationship with the other entities held jointly and severally liable, since such a rule applicable by default is at odds with the concept of joint and several liability, as established by European Union law.

144 Second, the appellant companies submit that, by relying on the rule of liability in equal measure, the General Court erred in law by finding, at paragraph 236 of the judgment under appeal, that the Commission had not delegated to a national court or an arbitration panel the power to determine their respective contributions to payment of the fine. In fact, when the Commission omits to determine the share to be paid by each person jointly and severally liable, it delegates the power to do so, by implication, to a third party, that is, a national court or an arbitration panel, in breach of Article 7 EC.

145 Third, the appellant companies contend that, by rejecting their arguments alleging infringement of the principle of legal certainty and unlawful delegation of powers on the basis of the rule of liability in equal measures, the General Court failed to have regard to its obligation to provide adequate reasoning, since, in so doing, it altered the content of the contested decision by adding grounds which are, moreover, at odds with what was intended by the Commission.

146 The Commission is of the view that the plea alleging unlawful delegation of powers is a new plea and is therefore inadmissible and that it is, in any event, unfounded, since it is based on the incorrect premiss that the Commission has the power to determine the share of the fine to be paid by the joint and several debtors in the context of their internal relationship, whereas its power to impose penalties relates only how joint and several liability is to be imposed from an external perspective. On the other hand, it joins, in essence, in the criticism of the rule of liability in equal measure referred to by the General Court at paragraph 215 of the judgment under appeal, but requests the Court to substitute its own grounds for the purpose of rejecting the arguments alleging infringement of the principle of legal certainty and the principle that the penalty must be specific to the offender and the offence.

ii) Findings of the Court

147 First, the plea raised by the Commission that the Alstom group companies' argument alleging unlawful delegation of the power to impose penalties is inadmissible must be rejected.

148 Since a party must be able to challenge all the grounds for a judgment adversely affecting it, where the General Court has joined two cases and given a single judgment which answers all the pleas submitted by the parties to the proceedings before the Court, each of those parties may criticise the reasoning concerning pleas which, before the General Court, were raised only by the applicant in the other joined case, provided that that reasoning adversely affects it (judgment of 11 July 2013 in Case C-444-11 P Team Relocations and Others v Commission, paragraph 34).

149 As regards the substance, with regard first of all to the appellant companies' arguments directed against paragraphs 215 and 236 of the judgment under appeal, it should be noted that those arguments are based on the premiss, set out at paragraph 214 of that judgment, that the powers available to the Commission under Article 23(2) of Regulation No 1-2003 to impose a fine for which a number of legal persons forming part of a single undertaking are jointly and severally liable includes the exclusive power to determine the shares of the fine to be borne by those persons in the context of their internal relationship, once the fine has been paid in full to the Commission, following which the latter has no further interest in the matter.

150 The Court of First Instance erred in law in accepting that premiss.

151 The power to impose penalties available to the Commission is confined to determining the amount of the fine for the payment of which the legal entities forming part of the same undertaking are held jointly and severally liable, that is, the external determination of joint and several liability, and does not extend to determining the share of that amount to be borne by those persons who are jointly and severally liable in the context of their internal relationship (Commission v Siemens Österreich and Others and Siemens Transmission & Distribution and Others v Commission, paragraph 58).

152 On the other hand, where there is no contractual agreement as to the shares to be paid by those held jointly and severally liable for payment of the fine, it is for the national courts to determine those shares, in a manner consistent with European Union law, by applying national law (Commission v Siemens Österreich and Others and Siemens Transmission & Distribution and Others v Commission, paragraph 62).

153 It follows that the General Court erred in law by finding, in essence, at paragraph 215 of the judgment under appeal, that in the absence of any finding in the Commission's decision imposing joint and several liability for payment of a fine on a number of companies that some of the companies in the undertaking have a greater share of responsibility than others for the undertaking's participation in the cartel during a specific period, it must be presumed that they are equally liable and, accordingly, must pay equal shares of the amounts for which they have been held jointly and severally liable (Commission v Siemens Österreich and Others and Siemens Transmission & Distribution and Others v Commission, paragraph 69).

154 It also follows that the General Court was not entitled to base its decision on such a rule of liability in equal measure, applicable by default, in order to conclude, at paragraphs 216 and 236 of the judgment under appeal, respectively, that the penalised companies were in a position to ascertain, without ambiguity, the possible financial consequences of the imposition of the fine to be paid jointly and severally and that the Commission had not delegated its power to impose penalties to a national court or arbitration panel.

155 However, it should be noted that, if the grounds of a judgment of the General Court disclose an infringement of European Union law but its operative part is shown to be well founded on other legal grounds, such an infringement is not capable of bringing about the annulment of that judgment, and a substitution of grounds must be made (see, to that effect, inter alia, Joined Cases C-120-06 P and C-121-06 P FIAMM and Others v Council and Commission [2008] ECR I-6513, paragraph 187 and case-law cited).

156 In the light of the foregoing, it is apparent that, at paragraphs 216 and 236 of the judgment under appeal, the General Court was clearly entitled to conclude that it was necessary to reject the arguments alleging, respectively, infringement of the principle of legal certainty and unlawful delegation of the Commission's powers.

157 First, as the Commission does not have the power to determine how the fine imposed jointly and severally is to be allocated internally, each company cannot be required to infer from the decision imposing joint and several liability for payment of a fine with a number of other companies the share of the fine to be borne by it in its relationship with the other entities, once the fine has been paid in full to the Commission (Commission v Siemens Österreich and Others and Siemens Transmission & Distribution and Others v Commission, paragraph 66). In the absence of any contractual agreement, that share must be determined by a national court. Accordingly, the fact that that share was not determined in the Commission's decision imposing joint and several liability for payment of a fine cannot, of itself, constitute an infringement of the principle of legal certainty.

158 Second, as the power to determine how a fine imposed jointly and severally is to be allocated internally rests with a national court or arbitration panel, not with the Commission, the latter cannot in any event be criticised for unlawfully delegating such a power on the basis that it failed to determine in the contested decision the shares to be paid by those jointly and severally liable for the fine in the context of their internal relationship.

159 It follows from the foregoing considerations that the grounds of appeal thus relied on are manifestly unfounded and that it is necessary, on the legal grounds set out at paragraphs 157 and 158 above, which are to be substituted for those adopted by the General Court at paragraphs 216 and 236 of the judgment under appeal, to dismiss the appeal on that point.

160 Secondly and finally, it is also necessary to reject the argument alleging that the General Court infringed the obligation to provide adequate reasoning. The claim that the General Court substituted its own reasoning for that of the contested decision cannot be upheld. Indeed, in its review of the legality of that decision, the General Court was perfectly entitled to dismiss the pleas in question in reliance on grounds such as that affirming the rule of liability in equal measure, applicable by default, even though, in substantive terms, that ground proved to be incorrect in law.

161 In the light of all the foregoing, it must be concluded that Areva's second and third grounds of appeal and the third part of the second ground of appeal and the fourth ground of appeal relied on by the Alstom group companies are well founded, in so far as they claim that the Commission and the General Court imposed de facto joint and several liability as between Areva and Alstom and thus infringed the rules governing joint and several liability for payment of fines, which derive from the principle of legal certainty and the principle that the penalty must be specific to the offender and the offence.

3. Areva's fourth ground of appeal, alleging infringement of the principles of proportionality and equal treatment in the determination of the fine imposed on it

i) Arguments of the parties

162 Areva contends that, in the exercise of its unlimited jurisdiction, the General Court ought to have assessed whether the amount of the fine imposed on Areva was proportionate to the gravity and duration of the infringement and whether it was consistent with the principle of equal treatment. Applying those principles, the General Court should have reduced the maximum amount of the fine for which Areva was held jointly and severally liable.

163 The infringement of the principle of proportionality invoked arises from the fact that Areva was ordered to pay, jointly and severally, for an infringement that lasted only four months, a sum representing approximately half the sum that Alstom is required to pay, jointly and severally, for an infringement that lasted 12 years, or almost twice the amount of the fine that Alstom must pay alone for its direct participation in the cartel at issue for a period of four years.

164 The principle of equal treatment was also infringed, since the General Court upheld the contested decision in spite of the fact that, by that decision, having regard to the duration of the participation in the cartel in question, the Commission penalised Areva much more severely than Alstom, even though Alstom was one of the founders of the cartel, the total duration of its participation in the cartel was 47 times as long as Areva's and Alstom's turnover was greater than Areva's.

165 The Commission submits that this ground of appeal is inadmissible, since, in particular, it was not raised as a plea by Areva at first instance and does not constitute a plea involving a matter of public policy which the General Court should have raised of its own motion. As regards the substance, the Commission maintains that the determination of the fine imposed on Areva cannot be criticised because, inter alia, it was calculated in accordance with the Guidelines.

ii) Findings of the Court

166 First of all, with regard to the admissibility of the present ground of appeal, it should be noted, as the Advocate General also observed at point 189 of his Opinion, that in their application at first instance, the Areva group companies did not raise a plea alleging infringement of the principles of proportionality and equal treatment, by which they claimed that the fine imposed on Areva was unlawful owing to a breach of those principles. While it is true that, in their application, those companies alleged infringement of the principles of equal treatment and proportionality, that argument related to a completely different issue, namely the fact that Alstom and Areva T & D SA were held jointly and severally liable for payment of the fine.

167 The ground of appeal in question is therefore a new plea, which, in accordance with the case-law cited at paragraph 113 above, is inadmissible in an appeal before the Court of Justice.

168 Moreover, as also observed by the Advocate General at point 191 of his Opinion, while the transfer of Areva T & D SA to Alstom occurred between the period in which the action was brought at first instance and that in which the appeal was lodged, that does not constitute a new element of fact that could justify the conclusion that that ground of appeal is admissible, as that ground is not based on that element.

169 Nevertheless, Areva's fourth ground of appeal is admissible in that, by that ground, Areva takes issue with the General Court for failing to examine, in the exercise of its unlimited jurisdiction, whether the fine imposed on it jointly and severally with, inter alia, Areva T & D SA, was unlawful, by reason of an alleged infringement of the principles of proportionality and equal treatment and of an error in law by the General Court in exercising that jurisdiction.

170 As pointed out at paragraph 118 above, a plea which has its origins in the judgment under appeal may be relied on in an appeal.

171 In that regard, it should be noted that, in addition to carrying out a review of lawfulness as provided for by the FEU Treaty, the General Court has unlimited jurisdiction, conferred on it, in accordance with Article 261 TFEU, by Article 31 of Regulation No 1-2003, and which empowers it to substitute its own assessment for that of the Commission and, as a consequence, to cancel, reduce or increase the fine or penalty payment imposed (see, inter alia, Siemens and Others v Commission, paragraph 344, and Case C-586-12 P Koninklijke Wegenbouw Stevin v Commission [2013] ECR, paragraph 32 and the case-law cited).

172 The Court has also pointed out, however, that the exercise of unlimited jurisdiction does not amount to a review of the Court's own motion, and that proceedings before the Courts of the European Union are inter partes. With the exception of pleas involving matters of public policy, which the Courts are required to raise of their own motion, it is for the applicant to raise pleas in law against the contested decision and to adduce evidence in support of those pleas (Siemens and Others v Commission, paragraph 335).

173 The Court has also stated that that requirement, which is procedural in nature, does not conflict with the rule that, in regard to infringements of the competition rules, it is for the Commission to prove the infringements found by it and to adduce evidence capable of demonstrating to the requisite legal standard the existence of the circumstances constituting an infringement. What the applicant is required to do in the context of a legal challenge is to identify the impugned elements of the contested decision, to formulate grounds of challenge in that regard and to adduce evidence direct or circumstantial to demonstrate that its objections are well founded (Siemens and Others v Commission, paragraph 336).

174 It is not apparent that, in the exercise of its unlimited jurisdiction, as carried out at paragraphs 318 to 323 of the judgment under appeal, the General Court failed to have regard to those principles.

175 In those paragraphs, following its finding, at paragraph 317 of that judgment, that the applicants' pleas based on the principles of proportionality and equal treatment were well founded, in so far as the Commission increased the basic amount of the fine imposed on Alstom and the Areva Group companies by 50%, an increase identical to that increase imposed on Siemens, in respect of the aggravating circumstance of playing the role of leader in the infringement, the General Court went on to vary the fines imposed jointly and severally on Alstom and Areva by reducing that increase to 35% and 20%, respectively.

176 In that specific context, the General Court was not required, in the exercise of its unlimited jurisdiction, to examine of its own motion other complaints which could possibly be raised concerning the amount of the fine imposed on Areva on the basis of alleged infringement of the principles of proportionality and legal certainty, such as those raised by Areva in its appeal.

177 Lastly, according to well established case-law, it is not for this Court, when ruling on questions of law in the context of an appeal, to substitute, on grounds of fairness, its own assessment for that of the General Court exercising its unlimited jurisdiction to rule on the amount of fines imposed on undertakings for infringements by those undertakings of European Union law. Accordingly, only inasmuch as the Court of Justice considers that the level of the penalty is not merely inappropriate, but also excessive to the point of being disproportionate, would it have to find that the General Court erred in law, on account of the inappropriateness of the amount of a fine (Case C-70-12 P Quinn Barlo and Others v Commission [2013] ECR, paragraph 57).

178 With regard to the claim that the amount of the fine imposed on Areva was inappropriate, because it participated in the infringement in question for a short time only, it is not apparent that the amount of the fine imposed jointly and severally on Areva is excessive, to the point of being disproportionate.

179 As the Commission observed, that amount was calculated by applying the method set out in the Guidelines. In that context, it is common ground that Areva's participation in the cartel in question was of short duration and this is reflected in the fact that the starting amount of the fine was not increased to take account of the duration of the infringement, whereas the starting amount of the fine imposed on Alstom was increased by 155% to reflect the fact that it participated in that cartel for a total period of 15 years and 8 months.

180 However, the fact that Areva participated in the cartel for a short time only does not make Areva's infringement any less serious, as reflected in the calculation of the fine, in particular in the determination of the starting amount.

181 In accordance with Article 23(2) of Regulation No 1-2003, the amount of the fine must be determined by reference to the gravity of the infringement for which the undertaking concerned is held individually responsible and the duration of the infringement (Commission v Siemens Österreich and Others and Siemens Transmission & Distribution and Others v Commission, paragraph 52).

182 In those circumstances, Areva's fourth ground of appeal must be rejected.

4. Alstom's fifth ground of appeal, alleging infringement of the right to an effective legal remedy

i) Arguments of the parties

183 By their fifth ground of appeal, the Alstom group companies contend that, at paragraphs 223 to 230 of the judgment under appeal, the General Court misunderstood the scope of Alstom's first plea, alleging infringement of the right to effective judicial protection and, as a consequence, failed to address that plea.

184 In those paragraphs, the General Court considered the requirement of judicial review and, in particular, the fact that Alstom and Areva T & D SA had indeed enjoyed the right to have the contested decision reviewed by a court by the actual exercise of remedies. Areva's first plea before the General Court related to the freedom of choice to bring an action, which was limited by the effect of the fact that Alstom and Areva T & D SA were held jointly and severally liable for payment of the fine.

185 The Commission submits that, at paragraphs 223 to 230 of the judgment under appeal, the General Court adequately addressed the arguments put forward by the Alstom group companies at first instance.

ii) Findings of the Court

186 Contrary to the contentions of the Alstom group companies, it is apparent from a reading of paragraphs 223 to 230 of the judgment under appeal that the General Court adequately addressed Alstom's plea alleging infringement of the right to an effective legal remedy and did not, in that context, misunderstand the scope of Alstom's arguments.

187 In that judgment, the General Court, after referring to the relevant case-law, at paragraphs 224 to 227, considered, correctly, at paragraph 228, that the fact that the Commission had held Alstom and Areva T & D SA jointly and severally liable did not undermine the right of each of those companies, as addressees of the contested decision, to submit that decision to judicial review by actual use of the remedies guaranteed by EU law.

188 The Alstom group companies maintain that the General Court did not address the alleged restrictions on the freedom of choice to bring an action arising from the fact that Alstom and Areva T & D SA were held jointly and severally liable for payment of a fine. Thus, if Areva T & D SA brought an action, Alstom would be obliged to do likewise, in order to avoid having to pay the fine imposed in full, whereas if Areva T & D SA did not bring an action, it would have to pay the fine and any action brought by Alstom would no longer have any effect on the total amount of the fine.

189 It should be noted, in that regard, that those constraints are simply the unavoidable consequence of the fact that a fine was imposed on Alstom and Areva T & D SA for which those companies were held jointly and severally liable. While such a consequence may undoubtedly have an impact on the strategy of the undertakings held jointly and severally liable, it does not, of itself, entail a breach of the right to an effective legal remedy. Each entity held jointly and severally liable has the right and the opportunity to bring an action, which, moreover, both Alstom and Areva T & D SA did, as also noted by the General Court at paragraph 228 of the judgment under appeal.

190 It follows that the Alstom group companies' fifth ground of appeal must be rejected.

191 It is apparent from the examination of all the grounds of appeal put forward by the appellant companies that, first, Areva's second and third grounds and the third part of the second ground as well as the fourth ground of appeal relied on by the Alstom group companies must be upheld, in so far as they contend that the Commission and the General Court imposed de facto joint and several liability as between Areva and Alstom and thus infringed the rules governing joint and several liability for payment of fines, deriving from the principle of legal certainty and the principle that the penalty must be specific to the offender and the offence and, second, the appeals must be dismissed as to the remainder.

192 It follows, first of all, that the second indent of paragraph 3 of the operative part of the judgment under appeal must be annulled.

193 Next, as the state of the proceedings so permits, for the purpose of the first paragraph of Article 61 of the Statue of the Court of Justice of the European Union, this Court may properly give final judgment in the case.

194 It should be noted in that regard that the finding of joint of several liability in Article 2(c) of the contested decision is the same as the finding reached by the General Court, after exercising its unlimited jurisdiction and reducing the amount of the fine, in the second indent of paragraph 3 of the operative part of the judgment under appeal.

195 Therefore, as the appellant companies sought the annulment of Article 2(c) of the contested decision at first instance, that provision must be annulled on the same grounds as those which justified the annulment of the second indent of paragraph 3 of the operative part of the judgment under appeal, which are set out at paragraphs 129 to 142 above.

196 Lastly, under the unlimited jurisdiction conferred on it, in accordance with Article 261 TFEU, by Article 31 of Regulation No 1-2003, the Court considers that the rules governing joint and several liability will be given proper application by determining the amount of the fines in accordance with a method which, unlike that adopted by the Commission and the General Court, complies with the rules governing joint and several liability for payment of fines deriving from the principle of legal certainty and the principle that the penalty must be specific to the offender and the offence.

197 It follows that, in the light of what was stated at paragraph 138 above and bearing in mind the new names of some of the companies concerned, as alluded to at paragraph 14 above, a fine of EUR 27 795 000 must be imposed on Alstom, jointly and severally with Alstom Grid SAS, and a fine of EUR 20 400 000 must be imposed on Areva, T & D Holding and Alstom Grid AG, jointly and severally with Alstom Grid SAS.

VI - Costs

198 Under Article 184(2) of the Rules of Procedure of the Court of Justice, where the appeal is well founded and the Court itself gives final judgment in the case, the Court is to make a decision as to costs.

199 Under Article 138(1) of those rules, which apply to the procedure on appeal by virtue of Article 184(1) thereof, the unsuccessful party must be ordered to pay the costs if they have been applied for in the successful party's pleadings.

200 Pursuant to Article 138(3) of those rules, the parties are to bear their own costs where each party succeeds on some and fails on other heads. Under that provision, if it appears justified in the circumstances of the case, the Court may order that one party, in addition to bearing its own costs, pay a proportion of the costs of the other party.

201 As the appeals lodged by Areva and the Alstom Group companies have been granted in part, in addition to bearing its own costs in respect of both the proceedings at first instance and the appeals, the Commission must be ordered to pay one fifth of the costs incurred by Areva and the Alstom group companies relating to the proceedings at first instance and the appeals. Areva and the Alstom group companies must bear four-fifths of their own costs in respect of the proceedings at first instance and the appeals.

On those grounds, the Court (Fourth Chamber) hereby:

1. Annuls the second indent of paragraph 3 of the judgment of the General Court of the European Union of 3 March 2011 in Joined Cases T-117-07 and T-121-07 Areva and Others v Commission.

2. Annuls Article 2(c) of Commission Decision C(2006) 6762 final of 24 January 2007 relating to a proceeding under Article [81 EC] and Article 53 of the EEA Agreement (Case COMP-F-38.899 - Gas insulated switchgear).

3. For the infringements established in Article 1(b) to (f) of Decision C(2006) 6762 final, imposes a fine of EUR 27 795 000 on Alstom SA, jointly and severally with Areva Grid SAS, and a fine of EUR 20 400 000 on Areva SA, T & D Holding SA and Alstom Grid AG, jointly and severally with Alstom Grid SAS.

4. Dismisses the appeals as to the remainder.

5. Orders the European Commission, in addition to bearing its own cost in relation to both the proceedings at first instance and the appeals, to pay one fifth of the costs incurred by Areva SA, Alstom SA, T & D Holding SA, Alstom Grid SAS and Alstom Grid AG relating to the proceedings at first instance and the appeals.

6. Orders Areva SA, Alstom SA, T & D Holding SA, Alstom Grid SAS and Alstom Grid AG to bear four-fifths of their own costs relating to the proceedings at first instance and the appeals.