The Asia-Pacific Economic Cooperation (APEC) was established in 1989 with the purpose of eliminating trade and investment barriers in the Asia-Pacific region. There are currently 21 member nations. For a complete list see the APEC webpage. Since there is no treaty underlying the organization, all the initiatives proceed on a voluntary basis. There is no formal institutional structure and no dispute settlement process. Regular meetings between the leaders of the member countries have led the way toward the fulfillment of the goals of APEC.
The APEC webpage has a great deal more information about the purposes and activities of the organization.