A parallel $18 billion share swap deal between the British oil company and Russia’s state-controlled oil group Rosneft can now go ahead, the TNK-BP partners said in a joint statement, citing a decision by an arbitration panel.

Both moves are subject to the agreement of Rosneft.

Rosneft declined to comment, but the Russian billionaires that own the other half of TNK-BP expressed their satisfaction.

“We welcome today’s developments,” said Stan Polovets, chief executive of Alfa-Access-Renova (AAR), the consortium that represents the quartet of billionaire shareholders.

AAR had objected to the BP-Rosneft deal, saying that they had exclusivity on BP’s Russian exploits and has sought redress through legal challenges.