Case T-421/09 RENV: Judgment of the General Court of 15 December 2016 — DEI v Commission (Competition — Abuse of dominant position — Greek market for the supply of lignite and Greek wholesale electricity market — Decision establishing specific measures to correct the anti-competitive effects of an infringement of Article 86(1) EC, in conjunction with Article 82 EC — Article 86(3) EC — Obligation to state reasons — Proportionality — Freedom of contract)