The source said BP's case centres on a possible failure by Renova, the investment vehicle of businessman Viktor Vekselberg, a member of the Moscow-based consortium that owns half of TNK-BP, to offer new energy projects to TNK-BP, in breach of the shareholder agreement.
BP's landmark drilling deal with top Russian oil producer and TNK-BP rival Rosneft collapsed in the face of opposition from the consortium, which said BP had violated the shareholder agreement by failing to offer the deal to TNK-BP.
The case appears to mirror that filed by the Alfa-Access-Renova consortium, which ultimately led Rosneft and BP to back down from their deal.
"BP is trying to create problems in order to get revenge," the source said.
The Renova source said the nature of the complaint was unclear. BP's Moscow spokesman was not immediately available for comment.
The AAR consortium is also suing BP for damages, saying the failed deal hurt its relationship with Rosneft and the regulators.
Kommersant business daily said BP was alleging that Vekselberg, who also has extensive mining, construction and technology investments through his Renova Group, had violated the shareholder agreement by operating oil and gas assets independently without offering them to TNK-BP.
The TNK-BP shareholder agreement requires both sides to offer new business opportunities in Russia to the TNK-BP board before pursuing them independently.
Kommersant said the assets in question were gas and gas distribution assets held through Vekselberg's utility holding, Integrated Energy Systems (IES), as well as the refuelling complex at Yekaterinburg's airport, where Renova is financing renovation work.
Vekselberg ran TNK-BP's gas business as a senior executive for some years, and Renova is working on a deal to sell some of IES's power generation assets to Gazprom's utility business in a deal that would make him a minority shareholder in an enlarged Gazprom utility business.
Forbes magazine put the fortune of Viktor Vekselberg at $13 billion in April. His wealth comes largely from TNK-BP and a stake in aluminium giant RUSAL , of which he is chairman, but he also has businesses in engineering and solar energy.
EurActiv with Reuters