LONDON (REUTERS) - A US$24 billion (S$32 billion) deal to build Britain's first new nuclear power station in decades was signed behind closed doors in London on Thursday (Sept 29) in a low-key ceremony that underlined Prime Minister Theresa May's cautious approach to the Franco-Chinese project.

Journalists were not invited to the event but the government said the contract had been formally signed at a ceremony attended by Britain's Business Secretary Greg Clark, French Foreign Minister Jean-Marc Ayrault and China's National Energy Administration Director Nur Bekri.

The no-frills event for the project in Hinkley, southwest England, to be built by France's EDF and part-funded by China, contrasted with the approach taken by May's predecessor David Cameron who courted Chinese investment during a lavish state visit laid on for President Xi Jinping last year.

"It's a good deal," France's Ayrault told reporters earlier in the day. "I know it has raised questions, particularly in France, but it represents an opportunity for the future of an entire industry."

The plan has been dogged by uncertainty for months.

It was only narrowly approved by the French firm's board and then put on hold for further review by May in July, just hours before a large signing ceremony was due to take place to celebrate the project, stunning Paris and Beijing.

It was finally given the green light earlier this month, after the government included the proviso that it would be able to block the sale of EDF's controlling stake. The government also said it would take a more cautious approach in future over foreign investment in big infrastructure projects.