Linklaters is advising BP on a high-stakes dispute after Russian shareholders of the UK company's local joint venture (JV) TNK-BP launched a claim to halt BP's planned alliance with Russian oil giant Rosneft.

Linklaters London head of litigation Michael Bennett was instructed to advise BP, after the billionaire shareholders who make up the Alfa-Access-Renova (AAR) consortium that owns 50% of TNK-BP filed for an injunction in the High Court earlier this week to block the planned Rosneft partnership.

A hearing has been set for Tuesday (1 February) which, if successful, is likely to see AAR and BP enter into arbitration proceedings. Linklaters has already been instructed by longstanding client BP to advise on the planned strategic partnership with the Russian state-owned Rosneft, which is being structured as a $16bn (£10.1bn) share swap.

Skadden is advising longstanding client AAR with a team led by London head of litigation and arbitration David Kavanagh alongside European head of M&A Scott Simpson.

It is reported that AAR is seeking the injunction on the grounds that the Rosneft deal would breach the TNK-BP shareholder agreement by not giving AAR the opportunity to participate in the tie-up with Rosneft.

A spokesperson for BP commented: "We believe we are in compliance with the shareholder agreement, and are honouring our obligations to the partners. We have kept, and will keep, AAR informed of the situation and will fully meet our obligations under the shareholder agreement to inform them."

It is unconfirmed who is advising AAR; although in a previous 2008 dispute regarding the TNK-BP alliance Lovells, SJ Berwin and Cravath Swaine & Moore advised AAR, while Linklaters and leading Russian independent firm Egorov Puginsky Afanasiev & Partners acted for BP. However, Hogan Lovells is believed to have secured an advisory role for AAR.

Rosneft is not part of the current dispute but is being advised by Freshfields Bruckhaus Deringer, its lead counsel on the deal, with London-based corporate partner Sebastian Lawson and Moscow-based associate Sergei Diyachenko leading.

If the tie-up goes ahead, BP will take a 9.5% stake in Rosneft, worth around $8bn (£5bn) while Russia's largest energy company will take a 5% stake in BP, backing an equity-linked partnership to pursue joint projects in the Russian Arctic shelf.