BRITISH Energy blamed quarterly losses of £115m announced yesterday on operating and one-off costs.

The group, which employs 500 people at Hartlepool Power Station, said its performance in the three months to June 30 had been affected by lower than expected output from its eight nuclear power stations.

The company - preparing to delist its shares as part of a Government-backed debt restructuring plan - was also unable to fully benefit from the recent sharp rise in electricity prices because it had protected itself against potential falls in the market by forward-selling its planned output.

Seasonal repairs and unplanned stoppages of more than 14 days at Sizewell B, Suffolk, Torness in East Lothian and Heysham, Lancashire, were blamed for the weaker nuclear output figure, which was down 12 per cent.

In June, British Energy showed signs of a trading improvement as it reported pre-tax profits in the year to March 31 of £232m - compared with losses of £4.3bn a year earlier.

Yesterday's first quarter results - the first time British Energy has published figures for the period - included UK operating losses of £36m.

The company said it was making progress with its planned restructuring - which received a boost on Thursday when Polygon Investment Partners abandoned its attempts to derail the package.

Polygon and another institutional investor had called a meeting of shareholders, saying the planned debt-for-equity swap, which will hand control of the group to creditors, would leave them with an reduced stake.

British Energy said the agreement, which was recently backed by the European Commission, was the only option open to it, and that it faced administration if the proposals were blocked.

The plan, drawn up in October last year, involved banks and bondholders agreeing to write off £1.3bn in debt in return for control of the group.

British Energy also said it had launched a website - britishenergyuk.info - as well as a helpline to provide shareholders with the latest information on the company's restructuring process