The increasing demand for business agility mandates enterprises to collaborate on many frontlines to stay competitive and achieve high business performance. This has given rise to the issue of Cross Enterprise Collaboration (CEC), which refers to the collaboration of two or more enterprises in achieving common goals. CEC is facing major people, process and technological challenges today. IT setup in today?s enterprises makes them walled gardens, for good reasons, however, it is a prohibiter of successful collaboration among companies, their people, processes and sharing data. In this paper, we propose a framework that facilitates the understanding of major CEC challenges. Facilitating CEC require supporting process-level collaboration, and protection of shared IP and data with various enterprise-level and regulatory policies. We present a novel method and system for conversation- oriented, flexible and policy-aware process collaboration among people from different enterprises. We focus on the scenario of the collaboration of providers in multi-sourced IT services. The system is designed to be offered as a service in the cloud.