Case filed against China's limitations on rare earths export

China controls almost the entire world supply of rare earths.The 17 metals are used in electrical products, as well as many renewable energy devices.

Beijing has set quotas for exports of rare earths, which are critical to the manufacture of high-tech products. The US, Japan and the European Union have filed a case against China at the World Trade Organization, challenging its restrictions on rare earth exports.It is the first WTO case to be filed jointly by the US, EU and Japan.

They argue that by limiting exports, China, which produces more than 95% of the world's rare earth metals, has pushed up prices.

China denied the allegations, saying that it had enforced the quotas to ensure there was no environmental damage caused due to excessive mining.

"We think the policy is in line with WTO rules," said Chinese foreign ministry spokesman Liu Weimin.

"Exports have been stable. China will continue to export, and will manage rare earths based on WTO rules," he said.