CJEU, 2nd chamber, October 6, 2015, No C-23/14

THE COURT (Second Chamber),

1 This request for a preliminary ruling concerns the interpretation of Article 82 EC.

2 The request has been made in proceedings between Post Danmark A/S ('Post Danmark') and the Konkurrencerådet (Competition Council) concerning a retroactive rebate scheme implemented by that undertaking in 2007 and 2008 in respect of bulk advertising mail.

The dispute in the main proceedings and the questions referred for a preliminary ruling

3 At the time of the facts in the main proceedings, that is to say, in 2007 and 2008, Post Danmark was controlled by the Danish State and was responsible for the one-day delivery universal postal service, throughout Danish territory, for letters and parcels, including bulk mail, weighing less than 2 kg. It was required to apply a tariff scheme under which the prices of services covered by the universal service obligation could not differ according to the place of destination.

4 In order to offset the universal service obligation and the uniform tariff scheme imposed on it, Post Danmark had a statutory monopoly on the distribution of letters, including - in the case of bulk mail - inter alia, direct advertising mail, weighing up to 50 grams.

5 Direct advertising mail is a segment of the bulk mail market, consisting in the distribution, in the context of marketing campaigns, of advertising mail of uniform content bearing the address of the addressee.

6 The order for reference states that Post Danmark implemented a rebate scheme in respect of direct advertising mail in 2003, at a time when there was no competition on the market for the distribution of bulk mail and when the monopoly on the distribution of letters applied to all letters weighing up to 100 grams.

7 Those rebates applied to mailings presented by the customer in batches of at least 3 000 copies at a time, and in aggregate of at least 30 000 letters per year or representing an annual gross postage value of at least 300 000 Danish crowns (DKK) (approximately EUR 40 200). That rebate scheme contained a scale of rates from 6% to 16%, the latter being applicable to customers sending over 2 million items of mail per year, or items of mail of over DKK 20 million (approximately EUR 2 680 426) per year. The rebate scale was 'standardised', that is to say, all customers were entitled to receive the same rebate on the basis of their aggregate purchases over the reference period, namely one year.

8 At the beginning of the year, Post Danmark and its customers concluded agreements setting out estimated quantities of mailings for that year. The rebates were granted and invoicing took place periodically on that basis. At the end of the year, Post Danmark made an adjustment where the quantities presented were not the same as those in the initial estimate. The price of mailings for each customer was adjusted at the end of the year, with retroactive effect from the beginning of that same year, on the basis of the quantity of items of mail actually sent. The rebate rate finally applied was thus applicable to all mailings presented during the period concerned and not only to mailings exceeding the quantity initially estimated. In the same way, a customer whose volume of mailings proved to be lower than the quantity estimated had to reimburse Post Danmark.

9 The rebate scheme at issue in the main proceedings was applicable to all advertising mail bearing the address of the addressee, regardless of whether that mail was covered by Post Danmark's monopoly and of whether distribution took place in areas not covered by other operators. It is apparent from the order for reference that the progressiveness of the rebates applied to direct advertising mail was of most benefit to customers of average size, since the quantities presented by very large customers far exceeded the highest rate.

10 Bring Citymail Danmark A/S ('Bring Citymail') - a subsidiary of Poste Norge AS, a company responsible for the universal postal service in Norway - began to deliver business mail, including in the form of direct advertising mail, in Denmark on 1 January 2007. Bring Citymail offered a delivery service for that mail not within a period of one day of posting but within three days. That [three-day] service was available to approximately one million households in Copenhagen (Denmark) and the surrounding area, which corresponded to approximately 40% of all households concerned.

11 During the relevant period, Bring Citymail was Post Danmark's only serious competitor on the bulk mail market.

12 Bring Citymail withdrew from the Danish market in 2010 after suffering heavy losses. From the explanations provided in this connection, it appears it suffered losses of DKK 500 million (approximately EUR 67 010 654) on account of start-up costs and losses during the accounting periods 2006 to 2009.

13 Following a complaint lodged by Bring Citymail, the Konkurrencerådet found, by decision of 24 June 2009, that Post Danmark had abused a dominant position on the market for the distribution of bulk mail by applying, in 2007 and 2008, rebates in respect of direct advertising mail which had the effect of tying customers and 'foreclosing' the market, without being able to substantiate the efficiency gains that might have benefited consumers and neutralised those rebates' restrictive effects on competition.

14 The Konkurrencerådet found, inter alia, that Post Danmark was an unavoidable trading partner on the bulk mail market because it held over 95% of a market access to which was rendered difficult by high barriers and which was characterised by economies of scale. In addition, Post Danmark enjoyed significant structural advantages conferred, inter alia, by the statutory monopoly, given that during the relevant period, over 70% of all bulk mail in Denmark was covered by that monopoly, as well as unique geographical coverage encompassing all of Denmark.

15 According to the Konkurrencerådet, those factors obliged customers of that type of service to turn to Post Danmark for 70% of the mail in respect of which the latter held an exclusive right and for the significant proportion of bulk mail that was to be distributed beyond Bring Citymail's geographical coverage, so that in its own geographical area, Bring Citymail could compete on approximately 30% of mail only.

16 In addition, the Konkurrencerådet drew attention to the structure and content of the rebate scheme, in particular, its retroactive nature with a one-year period for the acquisition of rights and the amplitude of the rebate rates applied. According to the findings of the Konkurrencerådet, approximately two-thirds of direct advertising mail not covered by the monopoly could not be transferred from Post Danmark to Bring Citymail without an adverse impact on the scale of the rebates.

17 It inferred that that scheme resulted in an anti-competitive exclusionary effect on the market. The Konkurrencerådet held, contrary to what was submitted by Post Danmark, that it was not appropriate to base the assessment of the anti-competitive exclusionary effect on the market caused by the rebate scheme on the 'as-efficient-competitor' test, involving a comparison of the dominant undertaking's prices and costs. According to the Konkurrencerådet, in the light of the particular characteristics of the relevant market, it cannot be required, for the purposes of that comparison, that a new competitor be as efficient in the short term as Post Danmark.

18 By decision of 10 May 2010, the Konkurrenceankenævnet (Competition Appeals Tribunal) upheld the Konkurrencerådet's decision of 24 June 2009.

19 Post Danmark brought the case before the Sø- og Handelsretten (Maritime and Commercial Court), which took the view that, while it is established that to be contrary to Article 82 EC a rebate scheme, such as that at issue in the main proceedings, must be capable of having a certain exclusionary effect on the market, there is nevertheless uncertainty as to the criteria to be applied in order to determine whether such a scheme is, in the specific case, capable of having an exclusionary effect contrary to Article 82 EC.

20 In those circumstances, the Sø- og Handelsretten decided to stay the proceedings and to refer the following questions to the Court of Justice for a preliminary ruling:

'(1) What guidelines should be used to decide whether the application by a dominant undertaking of a rebate scheme with a standardised volume threshold having the characteristics referred to in the order for reference constitutes an abuse of a dominant position contrary to Article 82 EC?

In its answer the Court is requested to clarify what relevance it has to the assessment whether the rebate scheme's thresholds are set in such a way that the rebate scheme applies to the majority of customers on the market.

In its answer the Court is further requested to clarify what relevance, if any, the dominant undertaking's prices and costs have to the evaluation pursuant to Article 82 EC of such a rebate scheme (relevance of an "as-efficient-competitor" test).

At the same time the Court is requested to clarify what relevance the characteristics of the market have in this connection, including whether the characteristics of the market can justify the foreclosure effect being demonstrated by examinations and analyses other than an as-efficient-competitor test (see, in that regard, paragraph 24 of the [communication from the Commission entitled "Guidance on the Commission's enforcement priorities in applying Article 82 of the EC Treaty to abusive exclusionary conduct by dominant undertakings" (OJ 2009 C 45, p. 7)].

(2) How probable and serious must the anti-competitive effect of a rebate scheme having the characteristics referred to in the order for reference be for Article 82 EC to apply?

(3) Having regard to the answers given to Questions 1 and 2, what specific circumstances must the national court take into account in assessing whether a rebate scheme, in circumstances such as those described in the order for reference (characteristics of the market and the rebate scheme), has or is capable of having such a foreclosure effect in the specific case that it constitutes an abuse covered by Article 82 EC?

In this connection, is it a requirement that the foreclosure effect should be appreciable?'

Consideration of the questions referred

First and second subparagraphs of Question 1 and first subparagraph of Question 3

21 By the first and second subparagraphs of Question 1 and the first subparagraph of Question 3, which it is appropriate to examine together, the referring court asks, in essence, the Court to clarify the criteria that are to be applied in order to determine whether a rebate scheme, such as that at issue in the main proceedings, is liable to have an exclusionary effect on the market contrary to Article 82 EC. The referring court also asks what relevance is to be attached, in the context of that assessment, to the fact that the rebate scheme is applicable to the majority of customers on the market.

22 According to the file placed before the Court, the rebate scheme operated by Post Danmark in 2007 and 2008 had three main features.

23 First, the rebate scale, which included rates from 6% to 16%, was 'standardised', that is to say, all customers were entitled to receive the same rebate on the basis of their aggregate purchases over an annual reference period.

24 Secondly, the rebates were 'conditional', in the sense that Post Danmark and its customers concluded agreements, at the beginning of the year, in which estimated quantities of mailings for that year were set out. At the end of the year, Post Danmark made an adjustment where the quantities presented were not the same as those that had been estimated initially.

25 Thirdly, the rebates were 'retroactive', in the sense that, where the threshold of mailings initially set was exceeded, the rebate rate applied at the end of the year applied to all mailings presented during the period concerned and not only to mailings exceeding the threshold initially estimated.

26 As regards the application of Article 82 EC to a rebate scheme, it should be recalled that, in prohibiting the abuse of a dominant market position in so far as trade between Member States could be affected, that article refers to conduct which is such as to influence the structure of a market where, as a result of the very presence of the undertaking in question, the degree of competition is already weakened and which has the effect of hindering the maintenance of the degree of competition still existing in the market or the growth of that competition (see, to that effect, judgments in Nederlandsche Banden-Industrie-Michelin v Commission, 322/81, EU:C:1983:313, paragraph 70, and British Airways v Commission, C 95/04 P, EU:C:2007:166, paragraph 66).

27 It is also settled case-law that, in contrast to a quantity discount linked solely to the volume of purchases from the manufacturer concerned, which is not, in principle, liable to infringe Article 82 EC, a loyalty rebate, which by offering customers financial advantages tends to prevent them from obtaining all or most of their requirements from competing manufacturers, amounts to an abuse within the meaning of that provision (see judgments in Nederlandsche Banden-Industrie-Michelin v Commission, 322/81, EU:C:1983:313, paragraph 71, and Tomra Systems and Others v Commission, C 549/10 P, EU:C:2012:221, paragraph 70).

28 So far as the rebate scheme at issue in the main proceedings is concerned, it must be observed that that scheme cannot be regarded as a simple quantity rebate linked solely to the volume of purchases, since the rebates at issue are not granted in respect of each individual order, thus corresponding to the cost savings made by the supplier, but on the basis of the aggregate orders placed over a given period. Moreover, it was not coupled with an obligation for, or promise by, purchasers to obtain all or a given proportion of their supplies from Post Danmark, a point which served to distinguish it from loyalty rebates within the meaning of the case-law referred to in paragraph 27 above.

29 In those circumstances, in order to determine whether the undertaking in a dominant position has abused that position by applying a rebate scheme such as that at issue in the main proceedings, the Court has repeatedly held that it is necessary to consider all the circumstances, particularly the criteria and rules governing the grant of the rebate, and to investigate whether, in providing an advantage not based on any economic service justifying it, the rebate tends to remove or restrict the buyer's freedom to choose his sources of supply, to bar competitors from access to the market, to apply dissimilar conditions to equivalent transactions with other trading parties or to strengthen the dominant position by distorting competition (judgments in British Airways v Commission, C 95/04 P, EU:C:2007:166, paragraph 67, and Tomra Systems and Others v Commission, C 549/10 P, EU:C:2012:221, paragraph 71).

30 Having regard to the particularities of the present case, it is also necessary to take into account, in examining all the relevant circumstances, the extent of Post Danmark's dominant position and the particular conditions of competition prevailing on the relevant market.

31 In that regard, it first has to be determined whether those rebates can produce an exclusionary effect, that is to say whether they are capable, first, of making market entry very difficult or impossible for competitors of the undertaking in a dominant position and, secondly, of making it more difficult or impossible for the co-contractors of that undertaking to choose between various sources of supply or commercial partners. It then has to be examined whether there is an objective economic justification for the discounts granted (judgment in British Airways v Commission, C 95/04 P, EU:C:2007:166, paragraphs 68 and 69).

32 As regards, in the first place, the criteria and rules governing the grant of the rebates, it must be recalled that the rebates at issue in the main proceedings were 'retroactive', in the sense that, if the threshold initially set at the beginning of the year in respect of the quantities of mail was exceeded, the rebate rate applied at the end of the year applied to all mailings presented over the reference period and not only to mailings exceeding the threshold initially estimated. On the other hand, a customer whose volume of mailings proved to be lower than the quantity estimated had to reimburse Post Danmark.

33 It is apparent from the case-law that the contractual obligations of co-contractors of the undertaking in a dominant position and the pressure exerted upon them may be particularly strong where a discount does not relate solely to the growth in purchases of products of that undertaking made by those co-contractors during the period under consideration, but extends also to those purchases in aggregate. In that way, relatively modest variations in sales of the products of the dominant undertaking have disproportionate effects on co-contractors (see, to that effect, judgment in British Airways v Commission, C 95/04 P, EU:C:2007:166, paragraph 73).

34 In addition, it must be pointed out that the rebate scheme at issue in the main proceedings was based on a reference period of one year. However, any system under which discounts are granted according to the quantities sold during a relatively long reference period has the inherent effect, at the end of that period, of increasing the pressure on the buyer to reach the purchase figure needed to obtain the discount or to avoid suffering the expected loss for the entire period (judgment in Nederlandsche Banden-Industrie-Michelin v Commission, 322/81, EU:C:1983:313, paragraph 81).

35 Consequently, as the Advocate General stated in points 37 and 38 of her Opinion, such a rebate scheme is capable of making it easier for the dominant undertaking to tie its own customers to itself and attract the customers of its competitors, and thus to secure the suction to itself of the part of demand subject to competition on the relevant market. That suction effect is further enhanced by the fact that, in the case in the main proceedings, the rebates applied without distinction both to the contestable part of demand and to the non-contestable part of demand, that is to say, in the latter case, to addressed advertising mail weighing less than 50 grams covered by Post Danmark's statutory monopoly.

36 In the case in the main proceedings, according to the file placed before the Court, for 25 of Post Danmark's largest customers, representing approximately one-half of the volume of transactions on the relevant market during the period at issue, approximately two-thirds of mail sent in the form of direct advertising mail not covered by the monopoly could not be transferred from Post Danmark to Bring Citymail without an adverse impact on the scale of the rebates. If that were established, a matter which it is for the referring court to ascertain, the incentive to obtain all or a substantial proportion of their supplies from Post Danmark would be particularly strong, reducing significantly customers' freedom of choice as to their sources of supply.

37 Moreover, as regards the standardisation of the rebate scale, whereby all customers were entitled to receive the same rebate on the basis of their aggregate purchases over the reference period, such a characteristic admittedly supports the conclusion that, in principle, the rebate scheme implemented by Post Danmark did not result in the application of dissimilar conditions to equivalent transactions with other trading parties, within the meaning of Article 82(c) EC.

38 However, the mere fact that a rebate scheme is not discriminatory does not preclude its being regarded as capable of producing an exclusionary effect on the market, contrary to Article 82 EC. Indeed, in the judgment in Nederlandsche Banden-Industrie-Michelin v Commission (322/81, EU:C:1983:313, paragraphs 86 and 91), the Court, having rejected the Commission's complaint that the discount system applied by Michelin was discriminatory, nevertheless held that it infringed Article 82 EC since it made dealers dependent upon Michelin.

39 As regards, in the second place, the extent of Post Danmark's dominant position and the particular conditions of competition prevailing on the bulk mail market, the order for reference states that Post Danmark held 95% of that market, access to which was protected by high barriers and which market was characterised by the existence of significant economies of scale. Post Danmark also enjoyed structural advantages conferred, inter alia, by the statutory monopoly on the distribution of letters weighing up to 50 grams that concerned 70% of all bulk mail. In addition, Post Danmark enjoyed unique geographical coverage encompassing all of Denmark.

40 An undertaking which has a very large market share is by virtue of that share in a position of strength which makes it an unavoidable trading partner and which secures for it freedom of action (judgment in Hoffmann-La Roche v Commission, 85/76, EU:C:1979:36, paragraph 41). In those circumstances, it is particularly difficult for competitors of that undertaking to outbid it in the face of discounts based on overall sales volume. By reason of its significantly higher market share, the undertaking in a dominant position generally constitutes an unavoidable business partner in the market (see judgment in British Airways v Commission, C 95/04 P, EU:C:2007:166, paragraph 75).

41 That fact, together with the factors mentioned in paragraph 39 above which contribute to clarifying the competitive situation on the relevant market, supports the conclusion that competition on that market was already very limited.

42 In those circumstances, it must be held that a rebate scheme operated by an undertaking, such as the scheme at issue in the main proceedings, which, without tying customers to that undertaking by a formal obligation, nevertheless tends to make it more difficult for those customers to obtain supplies from competing undertakings, produces an anti-competitive exclusionary effect (see, to that effect, judgment in Tomra Systems and Others v Commission, C 549/10 P, EU:C:2012:221, paragraph 72).

43 In addition, the referring court also wishes to know what relevance is to be attached, in the context of assessing the rebate scheme implemented by Post Danmark, to the fact that that scheme applies to the majority of customers on the market.

44 The fact that the rebates applied by Post Danmark concern a large proportion of customers on the market does not, in itself, constitute evidence of abusive conduct by that undertaking.

45 Indeed, in a case that concerned, inter alia, the assessment of the loyalty rebates applied by a dominant undertaking, the Court held that there was no need to ascertain the number of contracts which contained the clause at issue and the number which did not (judgment in Suiker Unie and Others v Commission, 40/73 to 48/73, 50/73, 54/73 to 56/73, 111/73, 113/73 and 114/73, EU:C:1975:174, paragraph 511).

46 However, the fact that a rebate scheme, such as that at issue in the main proceedings, covers the majority of customers on the market may constitute a useful indication as to the extent of that practice and its impact on the market, which may bear out the likelihood of an anti-competitive exclusionary effect.

47 Lastly, should the referring court find that there are anti-competitive effects attributable to Post Danmark, it should be recalled that it is nevertheless open to a dominant undertaking to provide justification for behaviour liable to be caught by the prohibition set out in Article 82 EC.

48 In particular, a dominant undertaking may demonstrate that the exclusionary effect arising from its conduct may be counterbalanced, or outweighed, by advantages in terms of efficiency which also benefit the consumer (see judgments in British Airways v Commission, C 95/04 P, EU:C:2007:166, paragraph 86, and TeliaSonera Sverige, C 52/09, EU:C:2011:83, paragraph 76).

49 In that last regard, it is for the dominant undertaking to show that the efficiency gains likely to result from the conduct under consideration counteract any likely negative effects on competition and consumer welfare in the affected markets, that those gains have been, or are likely to be, brought about as a result of that conduct, that such conduct is necessary for the achievement of those gains in efficiency and that it does not eliminate effective competition, by removing all or most existing sources of actual or potential competition (judgment in Post Danmark, C 209/10, EU:C:2012:172, paragraph 42).

50 In the light of the foregoing considerations, the answer to the first and second subparagraphs of Question 1, and the first subparagraph of Question 3, is that in order to determine whether a rebate scheme, such as that at issue in the main proceedings, implemented by a dominant undertaking is capable of having an exclusionary effect on the market contrary to Article 82 EC, it is necessary to examine all the circumstances of the case, in particular, the criteria and rules governing the grant of the rebates, the extent of the dominant position of the undertaking concerned and the particular conditions of competition prevailing on the relevant market. The fact that the rebate scheme covers the majority of customers on the market may constitute a useful indication as to the extent of that practice and its impact on the market, which may bear out the likelihood of an anti-competitive exclusionary effect.

The third and fourth subparagraphs of Question 1

51 By the third and fourth subparagraphs of Question 1, the referring court asks, in essence, the Court to clarify the relevance to be attached to the as-efficient-competitor test in assessing a rebate scheme under Article 82 EC.

52 Given that the referring court has mentioned, in the fourth subparagraph of Question 1, the communication from the Commission entitled "Guidance on the Commission's enforcement priorities in applying Article 82 of the EC Treaty to abusive exclusionary conduct by dominant undertakings", it must be observed, as a preliminary point, that that document merely sets out the Commission's approach as to the choice of cases that it intends to pursue as a matter of priority; accordingly, the administrative practice followed by the Commission is not binding on national competition authorities and courts.

53 The application of the as-efficient-competitor test consists in examining whether the pricing practices of a dominant undertaking could drive an equally efficient competitor from the market.

54 That test is based on a comparison of the prices charged by a dominant undertaking and certain costs incurred by that undertakings as well as its strategy (see judgment in Post Danmark, C 209/10, EU:C:2012:172, paragraph 28).

55 The as-efficient-competitor test has been specifically applied by the Court to low-pricing practices in the form of selective prices or predatory prices (see, in respect of selective prices, judgment in Post Danmark, C 209/10, EU:C:2012:172, paragraphs 28 to 35, and in respect of predatory prices, judgments in AKZO v Commission, C 62/86, EU:C:1991:286, paragraphs 70 to 73, and France Télécom v Commission, C 202/07 P, EU:C:2009:214, paragraphs 107 and 108), and margin squeeze (judgment in TeliaSonera Sverige, C 52/09, EU:C:2011:83, paragraphs 40 to 46).

56 As regards the comparison of prices and costs in the context of applying Article 82 EC to a rebate scheme, the Court has held that the invoicing of 'negative prices', that is to say, prices below cost prices, to customers is not a prerequisite of a finding that a retroactive rebate scheme operated by a dominant undertaking is abusive (judgment in Tomra Systems and Others v Commission, C 549/10 P, EU:C:2012:221, paragraph 73). In that same case, the Court specified that the absence of a comparison of prices charged with costs did not constitute an error of law (judgment in Tomra Systems and Others v Commission, C 549/10 P, EU:C:2012:221, paragraph 80).

57 It follows that, as the Advocate General stated in points 61 and 63 of her Opinion, it is not possible to infer from Article 82 EC or the case-law of the Court that there is a legal obligation requiring a finding to the effect that a rebate scheme operated by a dominant undertaking is abusive to be based always on the as-efficient-competitor test.

58 Nevertheless, that conclusion ought not to have the effect of excluding, on principle, recourse to the as-efficient-competitor test in cases involving a rebate scheme for the purposes of examining its compatibility with Article 82 EC.

59 On the other hand, in a situation such as that in the main proceedings, characterised by the holding by the dominant undertaking of a very large market share and by structural advantages conferred, inter alia, by that undertaking's statutory monopoly, which applied to 70% of mail on the relevant market, applying the as-efficient-competitor test is of no relevance inasmuch as the structure of the market makes the emergence of an as-efficient competitor practically impossible.

60 Furthermore, in a market such as that at issue in the main proceedings, access to which is protected by high barriers, the presence of a less efficient competitor might contribute to intensifying the competitive pressure on that market and, therefore, to exerting a constraint on the conduct of the dominant undertaking.

61 The as-efficient-competitor test must thus be regarded as one tool amongst others for the purposes of assessing whether there is an abuse of a dominant position in the context of a rebate scheme.

62 Consequently, the answer to the third and fourth subparagraphs of Question 1 is that the application of the as-efficient-competitor test does not constitute a necessary condition for a finding to the effect that a rebate scheme is abusive under Article 82 EC. In a situation such as that in the main proceedings, applying the as-efficient-competitor test is of no relevance.

Question 2 and the second subparagraph of Question 3

63 By Question 2 and the second subparagraph of Question 3, which should be answered together, the referring court asks, in essence, whether Article 82 EC must be interpreted as meaning that, in order to fall within the scope of that article, the anti-competitive effect of a rebate scheme, such as that at issue in the main proceedings, must be, on the one hand, probable and, on the other, serious or appreciable.

64 As regards, in the first place, the likelihood of an anti-competitive effect, it is apparent from the case-law cited in paragraph 29 above that, in order to determine whether a dominant undertaking has abused its position by operating a rebate scheme, it is necessary, inter alia, to examine whether that rebate tends to remove or restrict the buyer's freedom to choose his sources of supply, to bar competitors from access to the market, to apply dissimilar conditions to equivalent transactions with other trading parties or to strengthen the dominant position by distorting competition.

65 In that regard, and as the Advocate General stated in point 80 of her Opinion, the anti-competitive effect of a particular practice must not be of purely hypothetical.

66 The Court has also held that, in order to establish whether such a practice is abusive, that practice must have an anti-competitive effect on the market, but the effect does not necessarily have to be concrete, and it is sufficient to demonstrate that there is an anti-competitive effect which may potentially exclude competitors who are at least as efficient as the dominant undertaking (judgment in TeliaSonera Sverige, C 52/09, EU:C:2011:83, paragraph 64).

67 It follows that only dominant undertakings whose conduct is likely to have an anti-competitive effect on the market fall within the scope of Article 82 EC.

68 In that regard, the assessment of whether a rebate scheme is capable of restricting competition must be carried out in the light of all relevant circumstances, including the rules and criteria governing the grant of the rebates, the number of customers concerned and the characteristics of the market on which the dominant undertaking operates.

69 Such an assessment seeks to determine whether the conduct of the dominant undertaking produces an actual or likely exclusionary effect, to the detriment of competition and, thereby, of consumers' interests (judgment in Post Danmark, C 209/10, EU:C:2012:172, paragraph 44).

70 As regards, in the second place, the serious or appreciable nature of an anti-competitive effect, although it is true that a finding that an undertaking has a dominant position is not in itself a ground of criticism of the undertaking concerned (judgment in Post Danmark, C 209/10, EU:C:2012:172, paragraph 21), the conduct of such an undertaking may give rise to an abuse of its dominant position because the structure of competition on the market has already been weakened (see, to that effect, judgments in Hoffmann-La Roche v Commission, 85/76, EU:C:1979:36, paragraph 123, and France Télécom v Commission, C 202/07 P, EU:C:2009:214, paragraph 107).

71 Consequently, the Court has repeatedly held that a dominant undertaking has a special responsibility not to allow its behaviour to impair genuine, undistorted competition on the internal market (see judgment in Post Danmark, C 209/10, EU:C:2012:172, paragraph 23 and the case-law cited).

72 In addition, since the structure of competition on the market has already been weakened by the presence of the dominant undertaking, any further weakening of the structure of competition may constitute an abuse of a dominant position (judgment in Hoffmann-La Roche v Commission, 85/76, EU:C:1979:36, paragraph 123).

73 It follows that fixing an appreciability (de minimis) threshold for the purposes of determining whether there is an abuse of a dominant position is not justified. That anti-competitive practice is, by its very nature, liable to give rise to not insignificant restrictions of competition, or even of eliminating competition on the market on which the undertaking concerned operates.

74 It follows from the foregoing considerations that Article 82 EC must be interpreted as meaning that, in order to fall within the scope of that article, the anti-competitive effect of a rebate scheme operated by a dominant undertaking must be probable, there being no need to show that it is of a serious or appreciable nature.

Costs

75 Since these proceedings are, for the parties to the main proceedings, a step in the action pending before the national court, the decision on costs is a matter for that court. Costs incurred in submitting observations to the Court, other than the costs of those parties, are not recoverable.

On those grounds, the Court (Second Chamber) hereby rules:

1. In order to determine whether a rebate scheme, such as that at issue in the main proceedings, implemented by a dominant undertaking is capable of having an exclusionary effect on the market contrary to Article 82 EC, it is necessary to examine all the circumstances of the case, in particular, the criteria and rules governing the grant of the rebates, the extent of the dominant position of the undertaking concerned and the particular conditions of competition prevailing on the relevant market. The fact that the rebate scheme covers the majority of customers on the market may constitute a useful indication as to the extent of that practice and its impact on the market, which may bear out the likelihood of an anti-competitive exclusionary effect.

2. The application of the 'as-efficient-competitor' test does not constitute a necessary condition for a finding to the effect that a rebate scheme is abusive under Article 82 EC. In a situation such as that in the main proceedings, applying the as-efficient-competitor test is of no relevance.

3. Article 82 EC must be interpreted as meaning that, in order to fall within the scope of that article, the anti-competitive effect of a rebate scheme operated by a dominant undertaking, such as that at issue in the main proceedings, must be probable, there being no need to show that it is of a serious or appreciable nature.