Gazprom (Russia's state-run natural gas monopoly; world's biggest gas exploration and production company) Lukoil Rosneft (State-owned Russian oil and gas exploration company) Surgutneftegas Tatneft Northgas Transneft (Russia's pipeline monopoly) Bashneft (Russian oil refining company one of the largest producer of oil products in the country) Russneft Itera Novatek Rusneftegaz