This book constitutes the thoroughly refereed post-proceedings of the 7th International Workshop on Agent-Mediated Electronic Commerce, AMEC VII 2005, held in Utrecht, Netherlands in July 2005, as part of AAMAS 2005, and the third Workshop on Trading Agent Design and Analysis, TADA 2005, held in Edinburgh, UK in August 2005, in the course of the IJCAI 2005 conference meetings. The seven revised full AMEC 2005 papers presented were carefully selected.

 This book constitutes the thoroughly refereed post-proceedings of the 4th International Workshop on Agent-Mediated Electronic Commerce, AMEC 2002, held in Bologna, Italy in July 2002 during the AAMAS 2002 conference. The 20 revised full papers presented together with an introductory survey by the volume editors were carefully selected and improved during two rounds of reviewing and revision. The book gives a unique overview of the state of the art of designing mechanisms and systems for agent-mediated e-commerce- The papers are organized in topical sections on electronic auctions, negotiations, and electronic markets.