This article aims to articulate business representation in the process towards creating a unified market by comparing the regional integration process in Europe in the 1980s and in Southeast Asia in the new millennium. Both the European Community (EC) and the Association of Southeast Asian Nations (ASEAN) adopted the creation of a single market as a feasible strategy to respond to an economic hardship. In this process, US business associations played a critical role in identifying problems and issues in promoting actual integration. As for local business, the existing business associations did not function effectively and a new association comprising individual business executives was formed. Importantly, an initiative to create a new association came not from the private sector in Europe but from the member states in Southeast Asia. This difference led to disparities in the relative influence of the two associations on the actual integration processes.