A new approach is proposed to address several key issues relating to interoperability for collaborative product development within networked organizations. The work innovatively combines (i) a two-phase semantic data mediation model to ensure interoperability, (ii) a cloud-based platform to enable complex collaboration scenarios and (iii) an implementation and the evaluation of the proposed approach in the aerospace industry. The latter demonstrates that data mediation delivered as a service drastically reduces cost and time needed for establishing and maintaining interoperability.