China, the world's biggest maker of solar panels, is preparing to set anti-dumping duties on imports of the raw material used to make the equipment after determining it was sold below cost, said two people with direct knowledge of the matter. The Ministry of Commerce has completed probes that determined the US and European Union are subsidising producers of polysilicon and that imports of the commodity harmed domestic companies, said the people, who asked not to be identified as they were not authorised to discuss the matter publicly. The ministry is holding off on setting duties until the EU issues its ruling on anti-dumping tariffs against Chinese-made solar equipment, which will be a factor in China's decision, the people said. The EU plans to levy tariffs of as much as 67.9 per cent on solar panels from China, with the measures to be announced by June 6, a commerce official from the bloc, who asked not to be identified, said this month. The US began a probe against Chinese manufacturers in 2011 and the EU in September 2012 after falling solar equipment prices led to the collapse of companies including United States-based Solyndra. China's import tax could be high as "the EU situation that we face is not positive", Lian Rui, a Beijing-based analyst at research company NPD Solarbuzz, said yesterday. Chinese producers of polysilicon, including GCL-Poly Energy Holdings and Daqo New Energy will benefit, he added. The Hong Kong-listed shares of GCL-Poly have jumped 14 per cent since Tuesday. Daqo rose 16 per cent to close at US$6.44 in New York on Wednesday. China began probes into US and EU polysilicon producers last year to determine if firms had dumped the material.