WSBPEL  opens up the possibility of applying a range of formal techniques to the verification of Web service behaviors from two points of view: constraints between activities within the same process and dependencies between activities of different processes. In a previous work, vie have described an approach for the verification of Web service compositions defined by a set of BPEL processes. The key aspect of such a verification task is the model adopted for representing the communications among the services participating to the composition. In this paper, we propose to extend this approach to handle dependencies between activities of different process orchestrations through message exchanges. Our aim is to enable supporting models of service choreography with multiple interacting Web services compositions, from the perspective of a collaborative distributed composition development environment. The process of behavior analysis moves from a single local process to that of modelling and analyzing the behavior of multiple processes across composition domains.