Japanese trading giant Mitsui Co. is extracting rare earths from China's discarded glass to avoid the country's quota restriction on the minerals since September this year, the 21st Century Business Herald reported.

The Ministry of Commerce recently received reports from rare earths companies in Sichuan that Mitsui and other Japanese trading firms are extracting the valuable metals from glass imported from China.

China banned exports of discarded glass on Nov. 1 this year.

The action could be seen as a "Trojan Horse" to acquire rare earths and circumvent China's quota control, an expert said.

China will further tighten the restrictions on shipments of rare earths to protect the metals deposit, the report said.

China's business press carried the story above on Thursday. China.org.cn has not checked the stories and does not vouch for their accuracy.