Mikhail Fridman, the biggest shareholder in TNK-BP (TNKBP.RS), oil major BP PLC's (BP) Russian venture that has been riven by squabbling among its shareholders, said the company was "open for offers" from a third partner in the future.

"Everything is possible and realistic," Fridman told the Kommersant newspaper in an interview published Thursday. "We are open for offers."

The billionaire resigned abruptly Monday as chief executive of TNK-BP, a sign of deepening tensions between BP and its Russian partners in the 50-50 venture.

Fridman said he was standing down as CEO because he is an interested party in the shareholder battle. He denied reports that the resignation had anything to do with the ascension of former first deputy minister Igor Sechin--a powerful ally of President Vladimir Putin--to CEO of Rosneft (ROSN.RS).

Fridman said he and his partners in the venture would like to swap their stakes in TNK-BP for shares in BP.

BP and AAR, the consortium through which the Russian shareholders, a group of Soviet-born billionaires led by Fridman, hold their stake, have clashed over governance at TNK-BP, Russia's No. 3 crude producer, since the company was formed in 2003. The relationship soured again last year after AAR blocked BP's efforts to make a deal with Russian state oil giant Rosneft without including TNK-BP.