ENERGY regulator Ofgem has said it has no plans to refer the `big six' suppliers to competition authorities - despite a survey showing nine out of 10 customers feel ripped off.

Households are braced for more price hikes after npower raised gas and electricity charges at the start of January.

Chancellor Alistair Darling was due to meet Ofgem chief Sir John Mogg today for an explanation of the rises. It comes as a survey showed 89 per cent of customers believe they are being ripped off.

But an Ofgem spokesman said: "There are no plans at the moment for a Competition Act referral. Britain has one of the most competitive energy markets in Europe, with changing market share between the companies, price differences and good levels of switching.

"We keep markets under constant review but we can only take action if we find evidence of anti-competitive behaviour."

Ofgem, which can fine companies up to ten per cent of their global turnover if it uncovers breaches of competition laws, added that 4m customers had changed energy providers in 2006, with a further 2.8m switching in the first seven months of last year.

The YouGov survey found that energy firms were the biggest source of rip-off complaints from consumers - ahead of rail firms, petrol companies, and dentists.

The `big six' are to announce record annual profits of around £4.5bn for 2007.