Oman Mining Company (OMCO) launched in 1979 to exploit three copper deposits in the region of Sohar close to the north-east coast. The company constructed concentrator, smelting and refining facilities at the site capable of producing 20,000 metric tons of copper a year. Production began in 1983 and in 1994 the plant migrated to an international role as a toll smelting operation, shipping in copper concentrate from the copper traders and returning it to them or to other destinations as copper cathode.