Gazprom 1980s, the Ministry of Gas Industry found large natural gas reserves in Siberia, the Ural region and the Volga region. The Soviet Union became a major gas producer. In August 1989, under the leadership of Viktor Chernomyrdin, the Ministry of Gas Industry was renamed the "State Gas Concern Gazprom", and became the Soviet Union's first state run corporate enterprise. In late 1991, when the Soviet Union dissolved, gas industry assets were transferred to newly established national companies, such as Ukrgazprom and Turkmengazprom. Gazprom kept assets located in Russia and secured a monopoly in the gas sector. In December 1992, when
Gazprom Neft These companies are developing fields in the Yamalo-Nenets and Khanty-Mansi autonomous areas and the Omsk, Tomsk, Tyumen and Irkutsk regions. Gazprom Neft also holds 50% stakes in three dependent companies: Slavneft, Tomskneft and Salym Petroleum Development. In 2010, Gazprom Neft partnered with Novatek to acquire 51%of SeverEnergia which owns Arktikgaz and Urengoil companies. In 2012, Gazprom Neft refined 43.3 million tonnes of oil. The company wholly or partly owns 5 oil refineries (the Omsk Oil Refinery, Moscow Oil Refinery, Slavneft-Yaroslavnefteorgsintez (YANOS) and two oil refineries in Pančevo and Novi Sad that belong to Naftna Industrija Srbije). The company operates around