The growth of Internet technologies has unleashed a wave of innovations that are having tremendous impact on the way organisations interact with their partners and customers. It has undoubtedly opened new ways of automating Businessto-Business (B2B) collaboration. Unfortunately, as electronic commerce applications are most likely autonomous and heterogeneous, connecting and coordinating them in order to build inter-organisational services is a difficult task. To date, the development of integrated B2B services is largely ad-hoc, time-consuming and requires an enormous effort of low-level programming. This approach is not only tedious, but also hardly scalable because of the volatility of the Internet, and the dynamic nature of business alliances. In this paper, we consider the efficient composition and execution of B2B services. Specifically, we present a framework through which services can be declaratively composed, and the resulting composite services can be executed in a decentral...