Germany's biggest utility, E.ON, has offered to sell its electricity grid in a deal with the European Commission that would protect the group from a damaging antitrust investigation into Europe's energy markets.

The multibillion-euro sale of E.ON Netz, which would include 4,800 megawatts of its 26,000 mW power capacity, puts E.ON at odds with Germany's Government, which has opposed efforts by Brussels to force “unbundling” on big European utilities. Peter Hintze, Germany's Economy Minister, yesterday expressed astonishment at E.ON's deal. “The timing of these events, when the Commission is trying to force through a very sharp position against a minority — it's a very questionable game,” he said.

The deal is likely to add to pressure on E.ON's rivals, including RWE, its fellow German utility, and Electricité de France to toe the Commission line and agree to sell power transmission networks, such as electricity and gas grids. Neelie Kroes, the Competition Commissioner, launched a campaign against abuse in the energy market in 2006 and last year proposed the unbundling of transport networks.

The Commission believes control of networks by dominant incumbent utilities bars rival energy suppliers from access to customers. Eight EU countries, including France and Germany, oppose restructuring and have offered a less drastic alternative of separate managements for the grid businesses.

In January, the Commission imposed a €38 million (£29 million) fine on E.ON for breaking a seal placed over a door at offices of E.ON Energie by Commission antitrust investigators.

A spokesman for E.ON said that the company wanted to “look forward”. E.ON said that it would sell its electricity transmission network to an operator with no interest in generation. The package of generating assets would be sold to competitors and it is believed that E.ON may seek to do asset swaps to gain market share in other European countries.

Sources close to E.ON suggested that the company had little to gain by continuing to fight the Commission. A source said: “It's totally fruitless.”

Analysts suggested that the electricity grid would fetch more than €1 billion and the generating assets were potentially worth several billion euros, depending on age and whether they were nuclear or coal plants.

Adam Dickens, a Société Générale analyst, said that E.ON had little reason to fight to keep an asset that was under regulatory pressure and yielding lower returns. The German regulator is squeezing utilities' rate of return from networks. “They would rather invest their money in non-regulated assets,” Mr Dickens said.

At greater risk is Electricité de France, which has an electricity grid worth €11 billion. France has accused Ms Kroes of pursuing an ideological agenda in seeking to break up Europe's big utilities, but the move by E.ON was yesterday hailed in Britain, where Ofgem, the regulator, has campaigned for more competition in continental European markets.

Ofgem said: “This is great news for British consumers ... E.ON's announcement today makes it very difficult for the other large energy companies to argue for retaining control of their transmission businesses.”

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