MOSCOW, June 16 (RIA Novosti) - Four Russian billionaire shareholders in TNK-BP sought to swap their 50% in the joint oil venture for a 7.6% stake in the British oil major, a Russian business daily said on Monday.

Kommersant said the Russian partners could get 7.6% in BP, whose market value is estimated at $215.5 billion. Its Russian venture is estimated at $32.8 billion.

Viktor Vekselberg, one of four Russian investors in the joint venture, said as quoted by Kommersant that BP had rejected the proposal, as well as the investors' demands on management and strategy.

The Russian oligarchs have demanded equal board representation, a cut in TNK-BP's foreign staff and the replacement of CEO Robert Dudley, who they accuse of putting British oil major BP's interests ahead of TNK-BP, including in oil projects abroad.

AAR - the consortium of Russian investors, also including German Khan, Mikhail Fridman and Len Blavatnik - said on Wednesday it would sue BP, which holds the other 50% in TNK-BP, for attempts to seize control in the joint venture. AAR said it planned legal action in the international arbitration court in Stockholm and in Russia.

BP Chairman Peter Sutherland said last week the Russian partners had resorted to methods used by Russia's corporate raiders to wrest control of the company.

Russian media reports on Monday quoted Vekselberg and Fridman - heads of Renova asset management company with 12.5% and Alfa Group investment with 25% in the oil venture respectively - as saying the asset swap was not longer being discussed.

"No way! The sale [of the 50% stake] is out of the question today. When the conflict is resolved, we will see," Vekselberg said.

Fridman said: "Any price [for the stake] proposed today would not correspond to the company's value in the future. TNK-BP has enormous growth prospects given the planned cuts in tax burden for oil producers in Russia" and growing oil prices, he said.

Set up in 2003, TNK-BP is Russia's third largest producer. It accounts for a quarter of BP's overall output.

Fridman told the paper the Russian shareholders' proposals were still on the table, but no new talks had been scheduled.

Speaking at a news briefing on Monday, the tycoon said the Russian investors sought to buy an extra 1% in the joint venture from BP to gain a controlling interest.

"We are not ready to sell, but we are ready to buy," he said.

Asked whether Gazprom had proposed buying TNK-BP stock from the Russian shareholders, Fridman said they had not received any offers from the energy giant.

"No one has contacted us or made any offers," he said.

Some analysts have suggested that the dispute could result in the oil company being bought up by a state-controlled energy giant as part of the Kremlin's campaign to strengthen its grip on the oil and gas sector.