241As regards the setting of fines for infringements of the competition rules, the Commission exercises its powers within the limits of the discretion conferred on it by Regulation No 17. It is settled case-law that traders cannot have a legitimate expectation that an existing situation which is capable of being altered by the Community institutions in the exercise of their discretion will be maintained (see Case 245/81Edeka [1982] ECR 2745, paragraph 27, and Case C-350/88Deiacre and Others v Commission [1990] ECR 1-395, paragraph 33).