Dana Petroleum, the Aberdeen-based oil firm formerly led by Tom Cross and sold to Korea National Oil Corporation in 2010 for £1.87 billion, suffered a plunge in profits last year.
The group reported profit before interest and tax of £326 million, down from £467m in 2011, which it blamed on rising production costs and exploration expenses. Its production levels were little changed and revenues increased slightly to £1.1bn.
The figures come as Dana starts a £1bn UK project, called the Western Isles but actually located in the Northern North Sea.
Chief executive Marcus Richards said 2012 had been “a year of solid progress” as Dana built the foundations for growth.
He said the Western Isles project was “extremely important” and should significantly boost production over the next five years.