Case T-343/08: Judgment of the General Court of 17 May 2011 — Arkema France v Commission (Competition — Agreements, decisions and concerted practices — Market in sodium chlorate — Decision finding an infringement of Article 81 EC and Article 53 EEA — Action for annulment — Admissibility — Imputability of the infringement — Fines — Aggravating circumstance — Repeat infringement — Mitigating circumstance — Cooperation during the administrative procedure — Significant added value)