Infighting between BP and its Russian partners in its TNK-BP oil venture erupted in the open on Tuesday, when the Russian billionaire shareholders publicly censured the company’s BP-backed chief executive and the two sides aired differences over strategy.

The public bickering over investment strategy and the role of foreign specialists at the company heightened the tension at TNK-BP amid speculation it was being targeted for takeover by Gazprom, the state-controlled energy conglomerate. Bankers familiar with the situation said growing pressure on the company to do a deal was creating friction between its shareholders as they sought an exit strategy.