BP, which owns 1.4 per cent of Rosneft, has called an emergency press conference at its London headquarters at 9pm tonight to announce full details of the deal.
Reports have suggested the deal would be in the form of a share swap with Rosneft taking a large stake in BP.
“Following recent press speculation, BP confirms that it is in discussions with Rosneft relating to a possible arrangement. A further announcement is to be made later today,” a BP spokesman said.
BP, which acquired the minority stake Rosneft stake in an IPO in 2006, has said previously that it did not intend to sell it.