Russian state-owned oil company Rosneft was closing in on control of TNK-BP yesterday, sending its powerful chief executive to London for talks after the four billionaires who own half the company agreed to sell their stake.

According to a source, Rosneft will pay the tycoons' AAR consortium $28 billion in a deal that could open the way for the holder of the other half of the company, British company BP, to pursue a strategic alliance with Rosneft.

The tentative deal, struck in Moscow on Tuesday, would dissolve a lucrative but troubled partnership and put Rosneft in control of more than half of Russia's production.

A senior minister said Rosneft had not yet requested the necessary approval for a deal. BP's decision in June to put its own stake up for sale put pressure on the oligarchs to sell their half of the business because, analysts say, the first to sell to Kremlin-backed Rosneft would likely get the higher price.

An exclusivity period during which only AAR could have bought BP's stake expired yesterday, and sources say Rosneft could yet table an offer that would also enable it to buy out the British oil major.

Igor Sechin, the company's CEO and Russia's most powerful energy official, was visiting London for talks with BP, according to a source.

BP has invited bids for its stake. With AAR looking to sell, it appears unlikely that it would submit a credible rival bid for BP's stake in TNK-BP.

Another source said BP had not received any offers for its stake. Rosneft is widely expected eventually to secure overall control of TNK-BP, which would create the world's largest publicly traded oil group with more than four million barrels per day in production.-Reuters