As conventional barriers to trade are dismantled, national competition policies have increasingly emerged as a key area of concern for future multilateral trade negotiations. Disputes over access to the Japanese market or over the regulation of transatlantic mergers have only highlighted the lack of coordination between the trade and competition policy communities. This paper presents a wealth of evidence on the role of public policy in perpetuating private anti-competitive practices that inhibit trade and investment. It proposes a promising framework for dealing with four key issues: market access, mergers, anti-dumping and investment liberalization. Despite debates about the involvement of the WTO, the paper shows that several issues could be addressed more effectively through reforms of domestic policies or through bilateral agreements.