The sale of JV with government backing to build plants in England and Wales could be signed in the near future, reported Bloomberg.
The deal is expected to be a boost for the British government, which seeks to upgrade grids, spur new reactors to replace aging power plants and cut pollution at a cost of £110bn.
Both the firms decided to sell Horizon after Germany said it will shut down all of its reactors following Fukushima Daiichi nuclear disaster in Japan.
Hitachi spokesperson Keisaku Shibatani was quoted by the new agency as saying that the company had put in a bid and declined to comment further.
An official at the UK Energy Department said that while the deal was a commercial matter for E.ON and RWE, there had been strong interest in buying Horizon.
