Curbs on polysilicon imports

China, the world's biggest consumer of solar-grade polysilicon, will tighten up on imports of the material after solar manufacturers took advantage of a rule that allowed them to avoid duties.

From September, it will suspend applications from solar companies to import polysilicon under the so-called "processing trade" rules, whereby material used in domestic manufacturing is exempt from import duties if the finished product－in this case solar cells used in panels－is then exported.

Polysilicon imports under processing trade rules surged after China imposed duties on purchases from the United States, South Korea and Europe, the Ministry of Commerce said in a statement on its website on Thursday.

The suspension is "mainly aimed at US polysilicon," said Wang Xiaoting, a Hong Kong-based analyst at Bloomberg New Energy Finance, given the high tariffs imposed on imports from that country.

China in January listed anti-dumping charges of as much as 57 percent for imports from US polysilicon makers including Hemlock Semiconductor Corp, REC Silicon ASA and SunEdison Inc.