By Sarah Tawton
Ofgem has announced plans to force energy firms to be more transparent about their finances.
The energy regulator said the new rules would see the UK's 'big six' suppliers face further scrutiny of their accounts.
It said the move would also make it easier for other suppliers to enter the market.
The big six - which include EDF Energy and British Gas - are being warned that they will face financial penalties if they do not trade fairly with independent suppliers.
Barriers to competition
The firms will also be forced to release their energy prices two years in advance, Ofgem said.
Last year, MPs criticised Ofgem for failing to make the finances of the big six suppliers transparent.
Announcing the latest move, the regulator said it would carry out a review of the terms under which the big six firms generate power and sell it to their supply arms.
Ofgem chief executive Andrew Wright said the regulator wanted to break down barriers to competition for new suppliers.
Reforms to help independent suppliers
He said: "These reforms give independent suppliers, generators and new entrants to the market, both the visibility of prices and opportunities to trade they need to compete with the largest energy suppliers.
"Almost two million customers are with independent suppliers, and we expect these reforms to help these suppliers and any new entrants to grow."
Mr Wright said Ofgem also wanted to help consumers find the best deal.
"We also want to ensure that information on revenues, costs and profits of the largest energy suppliers is as clear as possible for consumers," he said.
"Now we are taking further steps to ensure that it is published more quickly, and that it gives a robust, useful and accessible picture of company profits.
"Both of these reforms will help ensure competition bears down as effectively as possible on prices."