The European Union has asked the World Trade Organization to step into its dispute with China over the export of certain minerals.

The EU says Beijing is improperly using quotas and subsidies to limit exports of raw materials such as magnesium, phosphorus and petroleum coke from leaving the country.

The result has been artificially higher prices for the industrial materials outside China, which in turn enables Chinese companies to produce manufactured goods at a lower price, EU officials in Brussels said.

"China's restrictions on raw materials continue to distort competition and increase global prices, making conditions for our companies even more difficult in this economic climate," said EU trade chief, Catherine Ashton.

The EUobserver said Thursday the WTO request comes just ahead of this month's EU-China summit, and follows on the heels of similar requests made to the WTO by the United States and Mexico.