Gazprom, the state-controlled Russian gas company, today said it was in negotiations with Sibneft, the oil company controlled by Roman Abramovich, the billionaire owner of Chelsea Football Club.

"Negotiations are under way and I do hope they can finish before the year end," Alexander Medvedev, the head of Gazprom’s export arm Gazpromexport, told Reuters.

Earier this week, reports emerged that Gazprom had arranged for a $12 billion (£6.6bn) loan, the largest in Russian history, to finance its purchase of a 72 per cent stake in Sibneft. Later, a Russian anti-trust official stated that he saw no legal impediments to the deal.

Speculation that a deal could take place had circulated since June when President Vladimir Putin said talks were underway between the two companies.

Samuel Charap, of Eurasia Group, the political risk consultancy, said: "Rumours have circulated wildly since President Putin’s announcement ... so while the deal could be announced in the coming weeks, it is highly speculative to hazard a guess at an exact date."

Haggling over the sale price could delay the sale, Mr Charap added. The 72 per cent stake belongs to Mr Abramovich’s Millhouse Capital. At the close of trade yesterday, Sibneft was trading at 100.99 roubles or $3.55, making Millhouse’s stake worth $12.7 billion (£7bn).

Previously, Gazprom had stated that a fair sale price would be $3 per share, or $10.2 billion ($5.6bn) for the entire stake.

If the sale is completed it will leave TNK-BP as the only significant private Russian oil company without close government affiliation.

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