The four Soviet-born billionaires who co-own BP's lucrative but troublesome Russian joint venture on Wednesday notified the British giant of plans to raise their stake in the 50:50 holding.
The decision follows a July 1 announcement by BP that chronic boardroom disputes had forced it to seek a buyer for its stake in TNK-BP despite the firm producing nearly a third of the British group's entire oil output.
"AAR and BP both realize that a fundamental realignment in the ownership of TNK-BP is necessary," said Stan Polovets of the Alfa Access Renova consortium that represents the tycoons.
"We hope that BP will now engage with us constructively, particularly given the importance of TNK-BP to BP's overall position," the AAR chief executive said.
BP confirmed having entered "the next stage in the TNK-BP sales process" by receiving an offer from the Russian billionaires that will keep it from striking any outside deal for three months.
The group stressed that it "will (also) enter into negotiations with other interested parties," while cautioning that the latest developments did not necessarily mean a deal will be done.
BP has reaped nearly $20 billion in dividend payments since forming the TNK-BP venture in 2003 at the start of what promised to be a new era of Russian openness to investment from the world's biggest energy firms.
The venture has developed into one of the top 10 private oil producers in the world and is currently one of Russia's largest owners of so-called greenfield projects that focus on the development of new reserves.
But that upside has been clouded for BP by a history of tensions with the Russian government that has seen the group's executives forced out of the country and the firm lose access to vital fields.
A bitter dispute with co-owners who include Mikhail Fridman -- a banking and industry giant with ties to the Kremlin -- saw BP lose rights to a $16 billion Arctic exploration alliance it had agreed with state oil firm Rosneft last year.
That dispute and subsequent arguments over strategy and operational control saw BP seemingly wave the white flag and announce it was seeking a buyer for a stake the market believes may be worth more than $20 billion.
Western investors welcomed BP's intention to give up on a venture that has been increasingly viewed as a drag on the stock's performance because of the Russia-related risk.
But many Moscow analysts see BP simply maneuvering within a boarder power struggle that will not lead to any change in TNK-BP ownership any time soon.
They also believe that the four local tycoons are just as willing to sell their own stakes in TNK-BP in exchange for BP shares and billions of dollars in cash.
Ivestcafe analyst Grigory Birg said the tycoons were ready to accept 10 to 12 percent of BP shares and financial compensation after demanding a buyout of some $35 billion that could have ended last year's Arctic oil dispute.
Some market players also think Rosneft itself may eventually end up replacing the billionaires in TNK-BP through a multi-step arrangement that would take many months to complete.
Birg said that "a share swap between BP and Rosneft could be the next step" after the British firm acquires its Russian partners' holding -- a much more likely option for analysts than a buyout by the Russians.
BP has long sought to forge ties with a Russian state firm that could secure its footing in the world's largest energy production market and save it from the uncertainties accompanying President Vladimir Putin's 12-year rule.
The Financial Times recently reported that BP has already received interest from at least one Russian state-held energy company for its stake in TNK-BP.
Yet companies such as Rosneft have difficult relations with the Russian tycoons and would appear to be reluctant to create a tie-up with them instead of BP.