The owner of British Gas has revealed it could return more cash to shareholders, risking controversy as customers are hit with rising bills.
Energy giant Centrica is currently buying back £500 million of shares, and its boss Sam Laidlaw told the Sunday Telegraph it could extend the programme next year.
Centrica opted to return "surplus capital" to investors in February after pulling out of plans to build the next generation of nuclear power plants in Britain with EDF Energy, amid uncertainty over the project.
The report said Centrica has enough cash to fund a similar buyback programme again next year as investment in other UK power projects stalls and it generates earnings from North American asset purchases.
Mr Laidlaw said: "We have got the headroom but we haven't made any firm decisions."
Last month the group reported a 3.2% increase in profits in its residential energy arm £ 356 million as it cashed in on the freeze in the first half of the year - and also hinted at further price rises for hard-pressed customers.
The supplier pumped up earnings from the bitterly cold weather after raising tariffs by 6% in December.
First-half revenues from household supply of gas were up 16% to £3.7 billion, compared with the same period in 2012, as Britons cranked up the thermostats. Average residential consumption by volume was up 13% for gas and 1% for electricity.
Operating profits at parent company Centrica were up 9% from £1.45 billion to £ 1.58 billion.
Centrica said its profits would have been higher but were held back by a new duty to pay for energy efficiency measures in customers' homes, which helped push environmental costs up 37% for the period.
It warned that the scheme, which has landed it with a £1.4 billion bill, would ''inevitably impact on customer bills ultimately'' and that it was facing ''upward pressure on costs''.
Finance director Nick Luff said at the time: ''We will keep prices as low as we can for as long as we can. If prices do have to go up, we will delay it for as long as possible.''
Shares in the group have risen 13% since the buyback was announced.