* Low carbon price makes nuclear unattractive
* E.ON, RWE not made negative decision on UK nuclear
* Horizon due to choose reactor design in next weeks
LONDON, March 14 (Reuters) - German utility E.ON , which together with rival RWE plans to build new nuclear plants in Britain, said on Wednesday its appetite for investing in nuclear power had slowed down.
"Our appetite to boost nuclear with great energy has become smaller," said board member Klaus-Dieter Maubach during the company's 2011 results conference.
He said the low carbon price meant investments in nuclear power, which emits zero carbon, were unattractive and also mentioned time and cost overruns at new nuclear plants in Finland and France.
CEO Johannes Teyssen clarified the utility had not made a negative decision against the British nuclear new build project and a final investment decision was not due at this stage.
"The investment environment (for nuclear power) in the UK is friendlier than in other countries," Teyssen said during the same conference.
E.ON and RWE have created a joint venture under the name of Horizon and plan to build up to 6,000 megawatts of new nuclear plants in Britain by 2025, an investment worth more than 15 billion pounds ($23.60 billion).
"Our shareholders are committed to continuing to develop this option for investment, and that's what we're focused on. It's business as usual for Horizon," said a UK-based spokesman for Horizon.
The joint venture is due to select a reactor design for its first new nuclear project at Wylfa in Wales in the next weeks.
Horizon has to make a choice between EDF and Areva's EPR design and Westinghouse's AP1000, two designs undergoing safety approval by Britain's Office for Nuclear Regulation.
The British government is pushing through electricity market reforms to help incentivise investments in new power, which it sees as a contributor to curb carbon emissions.
Proposals include so-called contracts for difference which will make payments to producers of low-carbon power, including nuclear.
E.ON posted a net loss of 2.22 billion euros in 2011 as it was hit by Germany's decision to shut down its oldest nuclear plants in the wake of Japan's Fukushima accident and losses in its gas business.