Judgment of the General Court (Eighth Chamber) of 24 March 2011 - Viega v Commission (Case T-375/06) Competition - Agreements, decisions and concerted practices - Copper and copper alloy fittings sector - Decision finding an infringement of Article 81 EC - Participation in the infringement - Duty to state reasons - Fines - Relevant turnover - Attenuating circumstances 1. Competition - Agreements, decisions and concerted practices - Burden of proof - Degree of precision required of the evidence used by the Commission (Art. 81(1) EC) (see paras 32-34) 2. Competition - Agreements, decisions and concerted practices - Agreements between undertakings - Burden of proof - Statement of an incriminated undertaking challenged by other parties to the same agreement - Probative value - Assessment (Art. 81(1) EC) (see para. 35) 3. Competition - Administrative procedure - Commission decision finding an infringement - Burden of proving the infringement and its duration on the Commission - Extent of the burden of proof (Art. 81(1) EC) (see para. 36) 4. Competition - Agreements, decisions and concerted practices - Participation of an undertaking in anti-competitive initiatives - Tacit approval without public distancing sufficient to render the undertaking liable (Art. 81(1) EC) (see para. 52) 5. Competition - Agreements, decisions and concerted practices - Agreements and concerted practices constituting a single infringement - Burden of proof (Art. 81(1) EC)) (see para. 70) 6. Competition - Agreements, decisions and concerted practices - Relevant market - Delimitation - Criteria (Art. 81(1) EC) (see para. 81) Re: APPLICATION for annulment in part of Commission Decision C(2006) 4180 of 20 September 2006 relating to a proceeding under Article 81 [EC] and Article 53 of the EEA Agreement (Case COMP/F-1/38.121 - Fittings), and also, in the alternative, for a reduction in the fine imposed on the applicant in that decision. Operative part The Court: 1. Dismisses the action; 2. Orders Viega GmbH & Co. KG to pay the costs.