Case T-116/04: Judgment of the Court of First Instance of 6 May 2009 — Wieland-Werke v Commission (Competition — Agreements, decisions and concerted practices — Market for copper industrial tubes — Decision finding an infringement of Article 81 EC — Price-fixing and market-sharing — Fines — Principle that penalties must have a sound legal basis — Size of the market concerned — Deterrent effect — Duration of the infringement — Cooperation)