BP takes step to sell TNK-BP stake LONDON, July 19 (UPI) -- British energy company BP announced Thursday it was in entering into negotiations regarding the potential sale of its stake in TNK-BP. TNK-BP, Russia's third largest oil company, is a joint venture between BP and Alfa Access-Renova, an entity representing the interests of a group of Russian billionaires. The relationship between both sides has been acrimonious since at least 2008 when Bob Dudley, now chief executive officer at BP, left the top post at TNK-BP following disputes over the direction of the venture. BP said Thursday it was in the beginning stages of the potential sale of its stake in the joint venture following an AAR move to purchase part, or all, of BP's half. "As a result BP will tomorrow enter into a 90-day period of 'good faith' negotiations with Alfa Access-Renova as required by the TNK-BP shareholder agreement," the company said in a statement. BP is also able to and will enter into negotiations with other interested parties in parallel for the sale of its share in TNK-BP. It cautioned, however, that there was no guarantee that any transaction would take place. TNK-BP was formed in 2003.