In this paper we describe an approach to the modelling of virtual enterprise agreements. An important and ever-present issue in the set-up phase of such a virtual enterprise is the virtual enterprise contract. As one of the goals of virtual enterprises is to become operational quickly, the time consumed by the set-up phase must be reduced to a minimum. At the same time it has to be guaranteed that the outcome of this phase leads to a formally correct and executable agreement. Our approach aims at showing how to achieve a formal model of virtual enterprise contracts, which can later be executed and monitored in a particular automated contract management environment.