E.ON and RWE, Germany's two largest utilities companies, are set to announce the creation of a joint venture to build at least four nuclear reactors in the UK at a cost of around £20 billion, The Times has learnt.

E.ON and RWE will announce details of the venture to build at least 6 gigawatts of new generating capacity, possibly as early as today.

The capacity would be equivalent to replacing almost 10 per cent of Britain’s existing total installed power generating capacity.

The two companies are expected to propose the construction of reactors at two existing nuclear sites they already control at Wylfa, on the island of Anglesey, where RWE has been granted approval for a connection to the National Grid, and at Oldbury, beside the River Severn in Gloucestershire, where E.ON has recently obtained similar permission.

However, the companies are also expected to seek out further sites owned by the Government through the Nuclear Decommisioning Authority (NDA).

The joint venture could potentially lead to the construction of nuclear power stations with the same and possibly greater generating power than EDF’s proposals to build four reactors on sites formerly owned by British Energy, after its £12.5 billion takeover of the company

But in a blow for Areva, the French nuclear reactor designer, E.ON and RWE are understood to have backed away from a commitment to a specific reactor technology.

It is understood that the joint venture will be “technology neutral”, despite E.ON’s earlier pledge to back Areva's EPR reactor.

RWE is believed to be minded to back an alternative reactor designed by Toshiba-Westinghouse.

A spokesman for E.ON confirmed the creation of the joint venture.

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