Britain casts doubt on EDF's $24 billion nuclear project

* UK government to review plan by early autumn

* Fall in UK power price makes project more expensive

* Concerns raised about further delays to plant

* EDF was not warned about review - chief executive (Adds more comment from EDF CEO, Moody's, Durham academic, context on energy supply crunch in UK)

By Nina Chestney and William Schomberg

LONDON, July 29 (Reuters) - Britain has cast doubt on a $24 billion project with French utility EDF to build the UK's first new nuclear plant in decades, delaying a final decision on the plan just weeks after the Brexit vote ushered in a new prime minister.

The surprise decision to review the Hinkley Point C project was made public hours after the board of French state-controlled EDF voted to proceed with it.

The British government, which had been expected to sign contracts on Friday, said instead that it wanted to give the plans further consideration, postponing its verdict until early autumn.

The review came little more than a month after Britons voted to leave the EU in a referendum that forced the resignation of Prime Minister David Cameron - whose administration gave the initial go-ahead to the project - and the accession of Theresa May.

The vote, and the resulting economic uncertainty, threw doubt on the future of major British infrastructure projects, including the nuclear plant.

The two new reactors at Hinkley Point, in south-west England, would provide around 7 percent of Britain's electricity, helping to fill a supply gap as the country's coal plants are set to close by 2025.

The pouring of the first concrete is scheduled for mid-2019 but the plant's start-up date has been delayed several times due to regulatory hurdles, the fallout from the Fukushima nuclear disaster in Japan and EDF's deteriorating financial position.

Analysts and unions said the review under new Prime Minister May would likely delay the project further.

EDF's Chief Executive Jean-Bernard Levy said on Friday that the company had not been given advance warning of the review but that it was ready to organise the signing of contracts "as soon as all the parties involved are ready".

OVERPAYING?

Although EDF and Chinese partner China General Nuclear are responsible for the 18-billion-pound ($24 billion) cost of the project, Britain has committed to pay a minimum price for the power generated by the plant for 35 years.

Critics, including some British lawmakers and academics, say the country would be overpaying at that minimum price, which equates to double current market levels.

"Because of the fall in the energy price over the past 12 months, the project does look very expensive and there have been a lot of calls for other projects to be considered or for this to be taken back to the drawing board," said Oliver Salvesen, analyst at investment bank Jefferies.