BP has reportedly agreed a deal worth more than £17bn in a move that will see it take a stake in the world’s largest publicly listed oil producer.

The oil giant’s board is understood to have unanimously approved a plan to sell its 50% stake in its troubled TNK-BP joint venture to Rosneft, in return for cash and shares in the State-backed Russian energy firm.

The final details of the deal are still being thrashed out ahead of an announcement possibly as soon as today, but it is thought BP will receive up to £8bn and take a stake of between 15% to 20% in Rosneft, which would become the world’s biggest public oil company after the deal.