Virtual Enterprises (VEs) use software agents (SAs) to reduce costs, speed up operations, and increase efficiency and competitiveness. Agents can carry out negotiations and make contracts without any human intervention. This makes them useful both in negotiations to set up a VE and in contracting with VE partners. Agents raise legal problems about the relevance and validity of their actions. The law may not always offer a solution to agent-based interactions. This paper investigates whether current laws are suitable to regulating agents and what new rules may need to be introduced. This paper is partly based on research conducted for the EC project LEGALIST ( IST-2-004252-SSA, FP6 IST Programme).