One of Russia’s biggest oil companies, Tatneft, has been doing business in Crimea despite the risk of being placed on a U.S. sanctions blacklist, according to company documents and a source close to Tatneft. Most big Russian oil firms pulled out of Crimea after Washington imposed sanctions over Moscow’s annexation of the region from Ukraine in 2014 and threatened to put any company operating on the peninsula on its list of sanctioned entities. But a company called ZAO firma KONTs that operated a fuel station in the Crimean city of Sevastopol until at least September is controlled by units of Tatneft, according to ownership records in the state tax registry and the state statistics service that were collated by the Russian database SPARK. In addition, a document dated Sept. 4 that was seen by Reuters at the Sevastopol fuel station stated the fuel on sale there […]