Tullow Oil has agreed to sell its minority stake in a large onshore field in Congo to the Korea National Oil Company for $435m in order to focus on its core projects elsewhere in Africa.

The FTSE 100 company, which has an extensive asset portfolio in Africa, said it would divest its 11 per cent share in the M’Boundi field, one of the largest onshore fields to be discovered on the continent, to focus its attention on developments in Ghana and Uganda.