International environmental policy emerges out of the complex interaction of companies, social forces, states, and international institutions. Proponents of the globalization thesis argue that multinational corporations would increasingly turn to international fora to circumvent national controls, eclipsing the power of the state. This case study of corporate influence over the international negotiations to limit emissions of greenhouse gases suggests that an important distinction needs to be made between market enabling institutions, such as NAFTA and the WTO, in which capital is generally highly influential and supportive, and regulatory institutions, such as the climate convention. The paper employs theories of the state to demonstrate that for regulatory institutions, capital is likely to prefer acting at the national level where it enjoys well-charted and predictable channels of influence. Large companies are, however, rapidly building their capacity for coordinated political activity in the international arena.