OPEC Supply is an organization of OIL-producing countries that works to regulate the global supply of OIL. The acronym OPEC stands for the Organization of the Petroleum Exporting Countries, which was founded in 1960 and currently consists of 14 member countries. OPEC Supply works to stabilize the price of OIL by controlling the amount of OIL produced by its members. The organization also works to ensure that its members receive a fair price for their OIL. The term OPEC Supply is often used to refer to the collective production of OIL from all of the member countries. The three letter answer to the crossword puzzle is OIL.