PTT is the largest corporations in the country and also the only company from Thailand listed in Fortune Global 500 companies. The company ranks 81st among top 500 on the Fortune 500, and 180 on the Forbes 2000.[5][6] PTT was founded in 1978 (as Petroleum Authority of Thailand) as a state-owned enterprise, under Prime Minister General Kriangsak Chomanan's government. It was formed by a coupling between Thai Fuel Organization (Thai: องค์การเชื้อเพลิง) under Defense Energy Department and Thai Natural Gas Organization (Thai: องค์การก๊าซธรรมชาติแห่งประเทศไทย) under Ministry of Industry.[7][8]