Final answer:
The Organization of the Petroleum Exporting Countries (OPEC) was the first OMC with a formal organizational structure, a constitution, and bylaws.
Step-by-step explanation:
The Organization of the Petroleum Exporting Countries (OPEC) was the first to have a formal organizational structure with a constitution and bylaws. Founded in 1960, OPEC's mission is to coordinate and unify the petroleum policies of its Member Countries and ensure the stabilization of oil markets in order to secure an efficient, economic, and regular supply of petroleum to consumers. OPEC formalized its structure by adopting a constitution and bylaws, establishing its headquarters, and defining its principal organs, which include the Conference, the Board of Governors, and the Secretariat.