This book constitutes the refereed proceedings of the Third International IFIP/GI Working Conference on Trends Towards a Universal Service Market, USM 2000, held in Munich, Germany in September 2000. The 28 revised full papers presented together with three invited papers were carefully reviewed and selected from numerous submissions. The papers are organized in topical sections on electronic auctions and trading, Internet-based service markets, quality of service, mobile and distributed services, middleware architectures, service management, mobile agents and applications, and trends in data- and telecommunications.