( BBC ) - Plans have been put forward in Brussels that would open European energy markets to greater competition.
The European Commission put forward proposals that would force energy giants to "unbundle" operations.
This means that businesses which generate power and supply gas would not be allowed to control the electricity grid or pipeline networks.
Firms would be forced to either sell transmission networks or lease them to new operators.
The Commission says that the move would encourage new entrants to the sector as well as boost investment in infrastructure.
The proposals would also shield markets from outsiders such as Russia's Gazprom, which supplies about 25% of Europe's gas.
If it wanted to enter the market, it too would have to separate its supply and network businesses, under the regulations.
'Competitive'
A Commission report said the existing dominance in some countries of vertically integrated companies, meant that too many EU residents and firms "lack a real choice of supplier".
That dominance gave the energy titans "an inherent interest to limit new investment when this will benefit competition," it said.
Commission president Jose Manuel Barroso said that energy was a "driving force of our economy".
"We need a common European response to combat climate change, to achieve greater energy security and provide abundant energy at a fair price for citizens.
"This is only possible if we have a competitive gas and electricity market," he said.
The proposals have to approved by member states and the European Parliament, and it could be years before they take effect.
Independent regulator
The Commission also called for an independent EU energy agency to oversee national regulators.
Germany's E.ON and Electricite de France are among those that are tipped to be hardest hit.
Sam Laidlaw, the chief executive of British Gas-owner Centrica, said that the proposals were "an important step in providing more competitive energy markets for the benefit of Europe's energy customers".
"Ownership unbundling is the best way of opening up the closed shop that is the European energy market, of attracting investment and delivering better security of supply," he said.
"It should also allow better gas flows across Europe to supply our British Gas customers. For unbundling to work, though, a vital ingredient is watertight regulation, which the Commission is rightly proposing to implement."