43It must be borne in mind that the Commission has a margin of discretion when fixing fines, in order that it may direct the conduct of undertakings towards compliance with the competition rules (see Joined Cases T-236/01, T-239/01, T-244/01 to T-246/01, T-251/01 and T-252/01Tokai Carbon and Others v Commission [2004] ECR II-1181, paragraph 216 and the case-law cited).