2. Objectives and institutional setup 2.1 Objectives of competition authorities and sector regulators 2.2. Short description of different institutional models 2.3. Reasons for co-operation 3. Overview of co-operation tools 3.1. Legal framework for co-operation 3.2. Methods of co-operation 4. Co-operation On enforcement cases 4.1. Mergers 4.2. Antitrust 4.3. Why does co-operation work in some cases and not others?