British Gas owner Centrica is expected to write off £200m when it pulls out of the country's nuclear new build programme in the new year.
Centrica has the option of taking a 20 per cent stake in building nuclear power stations at Hinkley Point in Somerset and Sizewell in Suffolk alongside French group EDF.
However, chief executive Sam Laidlaw, right, is almost certain to confirm that Centrica will leave the project at the "final investment decision"in January, having spent virtually all its share of the £1bn in upfront costs that the companies had budgeted to the end of 2012.
This will mean that there is no British involvement left in the three consortiums established to build nuclear plants to bridge the country's impending energy gap. EDF is likely to seek a new partner and was cheered last week when Hinkley Point was granted the UK's first nuclear site licence in 25 years.
Centrica fears it cannot make the financial numbers work, as the cost of reactors has gone up from £4.5bn to £7bn each. It is likely to focus on US expansion instead.