The flourishing development of various forms of virtual enterprises requires new Information Technology facilities to exploit Internet to collaboratively perform tasks that go across the boundaries of the member enterprises. Representation and management of contracts between these enterprises have raised a number of issues and has not yet been fully resolved. In this paper we are concerned with representation of contracts involving enterprises participating to dynamic supply-chains. In order to describe constraints and obligations entitled in such constructs, we propose to use theMOISE + multi-agent organization description language. We use it within a multi-agent contract-management infrastructure in which each enterprise delegates the management of their out/in-sourcing contract to their dedicated agent that cooperate with the other agents to fulfill their commitments. We explore how this model can be used for such applications and more particularly to handle dynamic environments where virtual enterprises and thus the contracts, may change in a kind of reorganization process.