Energy prices are still rising

The company's domestic electricity charges are going up by 7% and its gas charges are rising by 12%.

Powergen announced the increases - adding �52 a year to a typical "dual fuel" bill - in July, blaming large rises in the wholesale price of energy.

British Gas has previously warned that its gas prices may rise too by a further 15% in the coming months.

A spokesman for British Gas, which is owned by the utility company Centrica, said no decision had been taken yet.

Oil prices blamed

Powergen's increases are the fourth for its gas customers since January last year, and the third it has imposed on its electricity customers.

The main reason for the higher charges has been the huge increase in the price of oil, which has gone up by 50% in the last 12 months to about $66 a barrel.

This has driven up the price of gas imported from the continent, where the wholesale price of gas is linked to the price of oil. In turn, this has made it much more expensive to generate electricity in the UK's gas-fired power stations.

Earlier this month five million customers of EDF Energy - which trades as London Energy, SWEB and Seeboard - also saw their bills rise for the fourth time since the start of last year.

20% increase

Typical household energy bills have now risen by about 20% in the last 18 months according to the consumer organisation Energywatch, which takes a dim view of the price increases.

"Oil producers and energy retailers are all doing very well - at the expense of the consumer," said Energywatch spokesman Graham Kerr.

Higher energy prices have also been a big factor behind the recent increase in the UK's inflation rate.