Hartlepool Power Station owner British Energy performed a £4.5bn magic act to haul itself back into the black.

The nuclear generator, which supplies about one-fifth of the UK's power, reported pre-tax profits in the year to March 31 of £232m - compared with losses of £4.3bn a year earlier.

But, the company warned a ruling on a key part of its ongoing financial overhaul had been delayed.

The East Kilbride-based group must wait until the autumn to discover if the European Commission has agreed to a financial restructuring plan, particularly over whether it meets rules on state aid.

A decision had been expected soon but it emerged yesterday that the Government had not been able to present all the necessary information to the Commission in time for it to make a decision before the summer break.

The restructuring plan, which was struck in October, involved banks and bondholders agreeing to write off £1.3bn in debt in return for control of the group.

As part of the deal, British Energy pledged to improve reliability and its operational performance, as well as secure European Commission support as the proposals will see the Government meet some decommissioning liabilities.

In the results, the company stressed that the restructuring remained subject to "a large number of significant uncertainties and important conditions".

The Government, which has kept the company afloat through previous loan agreements, has contingency plans in place if the restructuring fails.

The group's biggest plant is at Hartlepool with others at Heysham, Lancashire; Hinkley Point, Somerset; Hunterston, Ayrshire; Dungeness, Kent; Sizewell, Suffolk and Torness, East Lothian.

Last year's losses were inflated by a £3.6bn one-off accounting charge to cover the lower value of British Energy's nuclear plants.