Russian state giant Rosneft yesterday looked to cement its grip on oil production by announcing talks with BP over the British group’s lucrative stake in the TNK-BP venture it co-owns with four tycoons.

BP immediately said it “welcomed” the interest after a decade of acrimonious relations with Russian officials that threatened to imperil its future in the world’s largest energy production market.

The announcement follows weeks of denials by Russia’s largest oil company of any claims on a venture that has grown into the country’s fourth largest crude producer since being formed in 2003.

BP on June 1 said it was seeking buyers for its 50 per cent stake because of bruising boardroom battles with the powerful billionaires who jointly operate a venture now responsible for nearly a third of the British groups oil output.

“Rosneft announces that, in connection with BP’s recent statements regarding its intention to pursue a potential sale of its participation in TNK-BP, Rosneft has informed BP of Rosneft’s interest in a potential acquisition of such participation,” the company said in a statement. “As a result, the parties agreed to commence negotiations on this matter and signed a non-disclosure agreement.”

Rosneft said it had also informed the tycoons who operate their stake in TNK-BP through the Alfa Access Renova consortium of their interest in BP’s stake.

BP for its part said “that while conducting parallel discussions with Rosneft and any other interested parties, it will negotiate in good faith with Alfa Access Renova in accordance with its legal obligations.”

The state firm did not disclose the size of the stake under discussion. AAR last week announced opening negotiations on acquiring half of BP’s shares in the joint venture – a 25 per cent stake estimated to be worth at least €8.26 billion.