Alfa Group, controlled by billionaire Mikhail Fridman, is putting pressure on the management of Russian oil giant Rosneft and the oil company is ready to prove it in court, Rosneft said on Thursday. It said that its board of directors had received letters from Cyprus-based NBI Trading accusing them of attempts of diluting its stake in an oil equipment producer. \"An organized public attack on Rosneft connected with ongoing legal proceedings seems to aimed at putting the company and its directors under an informal pressure to solve issues in their interests, not by legal means and by damaging the company\'s reputation,\" Rosneft said in a statement. \"Given threats to interests of the company and its shareholders and attempts to exert pressure on Rosneft\'s management, the board of directors possesses evidence ... which could be presented in court if necessary to protect the rights and legitimate interests of Rosneft and its shareholders.\" Alfa Group is a shareholder in BP\'s Russian venture TNK-BP and is now at odds with the international giant over its intended cooperation with Rosneft. Earlier this year, BP struck a $16-billion deal with Rosneft which involved cooperation in developing the Russian Arctic and a share swap. But AAR, the consortium which includes Alfa and controls half of TNK-BP, said BP had violated TNK-BP\'s shareholder agreement by not offering the Rosneft cooperation possibility to TNK-BP first. The deal fell through and Rosneft signed an Arctic development contract with ExxonMobil instead.