Representatives of more than 30 countries have signed a deal to build the world's most advanced nuclear fusion reactor, aimed at developing a cheap and abundant energy source as the end of fossil fuels looms.

After months of wrangling, France edged out Japan last year in its bid to host the US$12.8 billion International Thermonuclear Experimental Reactor (ITER), which will be built at Cadarache, near the southern city of Marseille.

At a ceremony on Tuesday hosted by French President Jacques Chirac, representatives of China, the European Union, United States, Japan, India, Russia and South Korea signed the ITER agreement in the presidential Elysee Palace in Paris, finalising the project after years of negotiations.

China will provide 10 per cent of the funding for the project, as well as sending 30 experts to France to help construct the experimental reactor.

The ITER reactor will aim to turn deuterium extracted from seawater into fuel by mimicking the way the sun produces energy. Its backers say that would be vastly cleaner than existing nuclear reactors, and would offer almost limitless supplies of energy, with one litre of deuterium producing the same amount of energy as 300 litres of conventional petrol.

Unlike existing fission reactors, which release energy by splitting atoms apart, ITER would generate energy by combining atoms.

Source China Daily