This second edition provides an exhaustive analysis of the European Community rules relating to merger control, including the new EC Merger Regulation 139/2004 of 20 January 2004 which entered into force on 1 May 2004 and the latest interpretive notices adopted by the European Commission. The book draws upon the authors' detailed and practical knowledge of the subject as officials at DG Competition and practitioners specialising in this field, and will be updated through a companion website.