Sidanko also transliterated as SIDANCO (Сиданко; Russian: Сибирско-Дальневосточная нефтяная компания, lit. 'Siberian-Far Eastern Oil Company') was a Russian oil company, the 8th largest company in the country by revenue in 1995.[1] Sidanko owned several oil production units, including Chernogorneft and Udmurtneft.[2]