The Soviet-born billionaires owning half of Russian oil producer said late Monday that they could sell their stake in the company if their current bid for full ownership of the company fails.

The move aims to give the billionaires more options if their partner in TNK-BP, UK-based oil giant BP, sells its half of the joint venture to state-controlled Russian oil company OAO Rosneft, said Stan Polovets, chief executive of the Alfa-Access-Renova consortium. AAR holds the billionaires stake in TNK-BP.