OAO Gazprom, and its subsidiaries, operate gas pipeline systems. The Company is also an exporter of gas to European countries. The Company is engaged in oil production, refining activities and electricity generation. The Company and its subsidiaries are involved in exploration and production of gas, transportation of gas, domestic and export sale of gas, production of crude oil and gas condensate, and processing of oil, gas condensate and other hydrocarbons and sales of refined products. Other activities primarily comprise electric and heat energy generation and sales, storage of gas and construction. In February 2009, the Company acquired 51% interest in Naftna Industrija Srbije. In February 2009, it acquired 12.5% interest in OAO Beltransgas. As a result the Company increased its interest in OAO Beltransgas up to 37.5%. On April 24, 2009, the Company exercised the option agreement with ENI S.p.A. to purchase the additional 20% interest in OAO Gazprom Neft.