BP to kick off auction of £400m stake in Wytch Farm oil field

BP will kick-off the auction of its £400m controlling stake in Wytch Farm in Dorset, western Europe's biggest onshore oil field, in the next two weeks.

BP and adviser Société Générale are understood to be putting the finishing touches to the sale information for potential bidders. The process is part of a sell-off of a package of UK assets, though bankers question the proposed auction of three North Sea gas fields due to last month's Budget.

The Chancellor, George Osborne, introduced a windfall tax on North Sea oil operators, which is likely to dampen the value of the gas fields. The industry has warned that punitive tax rates of 81 per cent on older fields could deter investment in the North Sea.

However, BP's main focus at present is to push through its £10bn share-swap deal with Rosneft. The Russian co-owners of its existing Russian joint-venture, TNK-BP, are trying to block the Rosneft deal, arguing it was in breach of their own agreement.

A Stockholm arbitration panel will hold another hearing over the dispute tomorrow, though it already found against BP last month.

BP shares closed at 470p on Friday, up 16p on the start of the day's trading. This values the company at more than £85bn.