Case T-103/08: Judgment of the General Court of 13 December 2012 — Versalis and Eni v Commission (Competition — Agreements, decisions and concerted practices — Chloroprene rubber market — Decision finding an infringement of Article 81 EC — Price fixing and market sharing — Attributability of the unlawful conduct — Obligation to state the reasons on which a decision is based — Rights of the defence — Evidence of involvement in the agreement — Single and continuous infringement — Fines — Gravity and duration of the infringement — Repeat offending — Deterrence — Attenuating circumstances — Maximum turnover limit of 10 % — Cooperation — 2002 Leniency Notice — Equal treatment — Proportionality)