Service-Oriented Architecture (SOA) has emerged as an architectural style to foster enterprise interoperability, as it claims to facilitate the flexible composition of loosely coupled enterprise applications and thus alleviates the heterogeneity problem among enterprises. Meanwhile, Model-Driven Architecture (MDA) aims at facilitating the development of distributed application functionality, independent from its implementation using a specific technology platform and thus contributes to deployment in different platforms. In this paper we propose an MDA-based transformation technique for service composition. The contribution of the paper is two-fold. First, our approach shows how enterprise interoperability is supported by service composition at two different technical levels, namely at choreography and orchestration level. Second, the approach contributes to the management of changes that affect enterprise interoperability, by defining a (semi-)automated transformation from choreography to orchestrations in which the interoperability constraints specified at the choreography level are preserved.