Large-scale industrial systems involve nowadays hundreds of developers working on hundreds of models representing parts of the whole system specification. Unfortunately, few tool support is provided for managing this huge set of models. In such a context of collaborative work, the approach commonly adopted by the industry is to use a central repository and to make use of merge mechanisms and locks. In this article we present a collaborative model editing framework, peer-to-peer oriented, that considers that every developer has his own partial replication of the system specification and that makes use of messages exchange for propagating changes made by developers. Our approach has the advantage not to be based on a single repository, which is more and more the case in large-scale industrial projects.