From the BBC News site.
"Energy firm E.On is to raise gas prices by 26% and electricity prices by 16% on 22 August.
It is the third of the big six energy companies to increase prices for domestic customers during the summer.
It blamed an increase in wholesale costs, which it said had risen by more than 51% since February, for the latest rise - the second in a year.
E.On said dual-fuel customers would see an average annual increase in their bill of £227.
The average annual bill for an E.On customer paying by monthly direct debit would be £1,194 following the latest rise, up from £967. The average for those paying in other ways would be £1,259, the company said.
Those paying on a pre-payment meter would face an average annual bill of £1,298.
EDF Energy and British Gas raised their prices for domestic customers in July, and others are expected to follow suit.
Graham Bartlett, managing director of E.On's retail business, said that the company had tried to keep the increases as low as possible to protect customers.
I'm very aware of the effect that today's announcement will have on our customers and I recognise that this is a very tough time for everyone," he said.
This is E.On's second price rise for domestic customers this year. In February it put up gas bills by 15% and electricity tariffs by 9.7%.
The German-owned company has 5.5 million customers in the UK.
In the latest round of price rises in July, EDF Energy put up gas prices by 22% and electricity prices by 17%. Shortly afterwards, British Gas put up gas bills by a record 35% and electricity tariffs for its customers by 9%.
Adam Scorer, of watchdog Energywatch, said that the price rises were not a surprise owing to the picture across the industry.
"The brakes have come off the market," he told the BBC.
He said that the "good times" of self-sufficiency from the North Sea gas supply - which meant the UK's gas prices were the lowest in Europe - were over and so rising prices should be expected.
He said that consumers were waiting for the government to publish its intentions on tackling fuel poverty and for regulator Ofgem to complete its inquiry into competition in the energy market.
Gordon Lishman, director general of Age Concern, said the latest rises were a "huge blow" to those struggling to pay bills and called for the introduction of fuel vouchers by the government.
"We are extremely concerned that the one in three pensioner households likely to be living in fuel poverty by the end of the year will feel forced to cut back on essential food or fuel," he said.
E.On said it was helping those on pre-payment meters. It said it was the first energy company to match the prices of pre-payment meter customers and standard customers if they used the same amount of energy.
The difference in the average annual price between the payment methods is due to discounts for prompt payment that are only available to standard customers."
Regards.
