Centrica is returning £420m to shareholders after it revealed that it is selling three gas-fired power stations in Texas.
Centrica is selling the US power stations, with a combined capacity of 1,295 megawatts, to Blackstone for cash.
Centrica bought the three power plants for a total $331m (£202m, €242m) between 2004 and 2006, but said that it only made about £5m in profit last year from them.
However, it added that the power plants' combined asset value had increased as a result of energy market reforms in Texas.
In October, Centrica revealed that UK energy bills will rise by an average of 9.2%, taking the typical annual dual fuel bill up by more than £120 to a record of £1,465.
In its Autumn statement the UK government pledged to cut energy bills by £50 a year, via a series of measures.
Meanwhile, a number of the UK's 'Big Six' energy companies, which account for 99% of the country's energy sector, stated an intention to cut household bills or not raise prices until 2015..
British Gas said it was dropping household gas and electricity prices by an average of 3.2% and that these price reductions would take effect from 1 January.
Centrica, British Gas' parent company, said: "This price cut is based on the assumption that the government's proposed changes will be implemented in full."