Historically, governments have adopted legalized, integrated, and global rules to govern oligopolistic industries, such as shipping, chemicals, and industrial production. By contrast, they have adopted nonbinding and unintegrated rules and institutions to govern competitive industries, such as energy, agriculture, and mining, at the national or subnational scale. Considering that competitive producers face greater barriers to political collective action, what explains the form of global governance across these sectors? This article demonstrates that oligopolistic producers are more intensively and extensively regulated than competitive markets because producers in oligopolistic industries can more cost-effectively alter markets to meet environmental goals. Therefore, despite their political influence, oligopolies are regularly called upon to initiate and sustain market transformation on a global scale. New qualitative evidence from two treaty regimes governing different types of markets supports this theory, as well as new quantitative data on the full range of global environmental treaty regimes since World War II.