This paper explores the existing arrangements for multilateral regulation of large firms, and makes the case for balancing strengthened global corporate property rights with more explicit and enforceable social obligations. In a democratic market-based society, investors have legally enforceable rights but must also obey laws designed to protect labour, consumers and the environment, while competition regulations are designed to counter market power and business taxes ensure the provision of public goods. Strengthened multilateral co-operation in three related areas - investment, tax and competition - is under way. Although progress is slow and contested, the distinct interests of host and home countries are clear and the 'development dimension' broadly recognised. In marked contrast, corporate conduct on labour and environmental issues is still almost exclusively regulated at the national level. Moreover, external standards of international corporate responsibility in developing countries are set by voluntary initiatives at best, with market incentives rather than legal requirements constituting the basis for compliance. A better approach would be a multilateral definition of the obligations of international firms that is explicitly linked to the guarantee of property rights. These obligations might reasonably include international taxation, competition rules and stakeholder issues such as employment conditions and environmental protection. The ongoing process of regional integration - particularly in Europe - could present an additional opportunity for such a definition.