The Enterprise Act 2002 will radically change the UK's competition law regime. This text provides a comprehensive guide to the new merger control and market investigation procedures and the sanctions against cartel activities. Key features include: detailed guidance on the practical impact of these sweeping changes and the new powers of the competition authorities; explanation of how the new rules interact with the existing competition rules under the Competition Act 1998; and relevant sections and schedules of the Enterprise Act 2002, which are reproduced in full. This text brings together all of the UK competition rules in one single, concise reference book. It is intended for senior managers and commercial lawyers who need to be thoroughly briefed on the new systems and penalties from a very early stage.