In the first place, in essence, adoption by the Commission of Guidelines contributes to ensuring observance of the principle that penalties must have a proper legal basis. In that regard, the Guidelines determine, generally and abstractly, the method which the Commission has bound itself to use in setting the amount of fines and, consequently, ensure legal certainty on the part of the undertakings. In the second place, as can be seen from point 2 of the Guidelines, the latter fall within the statutory limits laid down by Article 23(2) and (3) of Regulation No 1/2003, an article that meets the requirements deriving from the principle that penalties must have a proper legal basis and the principle of legal certainty. Finally, in the third place, in adopting the Guidelines, the Commission did not exceed the limits of the discretion afforded it by Article 23(2) and (3) of Regulation No 1/2003.

In competition matters, the adoption of the Guidelines on the method of setting fines imposed pursuant to Article 23(2)(a) of Regulation No 1/2003, inasmuch as it fell within the statutory limits laid down by Article 23(2) and (3) of Regulation No 1/2003, contributed to defining the limits within which the Commission exercises its discretion under that provision and did not infringe the principle that penalties must have a proper legal basis, but was conducive to observance of it.

In competition matters, as is clear from the Guidelines on the method of setting fines imposed pursuant to Article 23(2)(a) of Regulation No 1/2003, the Commission’s methodology when calculating fines comprises two stages. First, the Commission determines a basic amount for each undertaking or association of undertakings. That basic amount makes it possible to reflect the gravity of the infringement at issue, by taking into account, in accordance with point 22 of those Guidelines, a number of factors specific to it, such as the nature of the infringement, the combined market share of all the undertakings concerned, the geographic scope of the infringement and whether or not the infringement has been implemented. Second, the Commission may adjust that basic amount upwards or downwards and, in that regard, take account of aggravating or mitigating circumstances which characterise the participation of each of the undertakings concerned.

As regards, more specifically, the first stage of the methodology for calculating fines, the basic amount of the fine is related to the ‘gravity of the infringement’ multiplier, which reflects the degree of gravity of the infringement as such. However, from that first stage, account is also taken of objective factors relating to the specific, individual circumstances of each of the undertakings participating in that infringement. The ‘gravity of the infringement’ multiplier applies in conjunction with two individual, objective parameters, namely, the value of the sales of goods or services achieved by each of them, to which the infringement directly or indirectly relates in the relevant geographic area within the European Economic Area, and the duration of the participation of each undertaking in the infringement as a whole.

Thus, an undertaking’s limited participation in the infringement found — that is to say, with regard to only one of three product sub-groups, indeed to only part of the sub-group — is taken into account by the Commission when calculating the basic amount of the fine. That basic amount is calculated, for each undertaking, on the basis of the value of its sales by Member State and for the relevant product sub-group.

However, the Commission was entitled to determine the basic amount of the fine on the basis, inter alia, of the gravity of the infringement taken overall. It cannot therefore be held that the Commission was obliged to take into account the particular intensity, if it were to be proven, of the collusive arrangements regarding one of the product sub-groups at issue.

(see paras 147, 148, 154, 171)