Less than three months after BP PLC's (BP) Russian billionaire partners in TNK-BP Ltd. derailed an Arctic alliance with Russia's top state oil company, the U.K. oil major is now hitting back at its partners, accusing one of them of violating their shareholder agreement.

A spokesman for Soviet-born business tycoon Viktor Vekselberg, who holds a 12.5% stake in the TNK-BP oil joint venture through his Renova Holding, said BP filed the arbitration notice Friday. The notice alleges that Renova violated the shareholder agreement between BP and Alfa-Access-Renova, or AAR, the consortium of billionaires who jointly control TNK-BP with the U.K. energy giant.

The move to fire back at its partners in the TNK-BP joint venture comes after BP's attempt to form a strategic alliance with Rosneft collapsed in May, following a legal victory by its partners in TNK-BP.

The billionaire partners claimed the Rosneft deal, which included an Arctic exploration project and a $16 billion share swap, would violate the TNK-BP shareholder agreement that requires BP and AAR to offer TNK-BP any energy proposals in Russia before working with others.

A person close to BP said Friday's notice is part of an ongoing arbitration case initiated by Alfa-Access-Renova. In a move designed to win billions of dollars in compensation from BP for alleged damage done to the joint venture, the Russian partners have asked a Stockholm arbitration panel to rule on whether the U.K. company breached their shareholder agreement when pursuing the tie-up with Rosneft.

"The arbitration is still ongoing and this forms part of it. The arbitration panel has never ruled on the breach," said the person close to BP, who asked not to be named. "It's the same arbitration hearing as before - it never stopped."

Meanwhile, a person close to AAR claimed the arbitration against Renova is a new move by BP aimed to "prolong the Stockholm arbitration and delay the ruling by the tribunal."

BP alleges that Vekselberg exceeded the shareholder terms by holding large natural gas and fuel assets through his IES Holding Ltd., Russia's largest private power supply company.

The Renova spokesman maintained that the holding company hasn't violated the terms of the TNK-BP shareholder agreement.

"The fact that BP is only now instigating proceedings leads us to believe that it might be building a defense against potential further attacks from AAR," said Dmitry Loukashov, analyst at VTB Capital.

In May, the parties were close to a deal under which BP and Rosneft would have bought out AAR's stake in TNK-BP for more than $32 billion in cash and stock. But the transaction collapsed at the last minute over legal disagreements. BP and AAR both acknowledge talks on a buyout are unlikely to be revived.

-By Jacob Gronholt-Pedersen and Alexis Flynn, Dow Jones Newswires; +7 495 232 9197; jacob.pedersen@dowjones.com