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WASHINGTON, Sept 8 (Reuters) - The United Steelworkers union said on Wednesday it planned to file a comprehensive trade case against "protectionist and predatory practices" used by China to support its clean energy sector.
The case, which the union plans to detail on Thursday, could ratchet up trade tensions across the Pacific at a time when many U.S. lawmakers are frustrated with China's currency and trade policies.
"China has utilized hundreds of billions of dollars of subsidies, performance requirements, preferential practices and other trade-illegal activities to advance their domination of the (alternative and renewable energy) sector," the steelworkers said in statement announcing their plans for a news conference to discuss the case.
The union is filing a nearly 6,000-page petition with the U.S. Trade Representative office asking it to launch an investigation into the group's charges.
It outlines "five major areas of protectionist and predatory practices utilized by the Chinese to develop their green sector at the expense of production and job creation here in the U.S.," the steelworkers said.
By law, the Obama administration has 45 days from the date of filing to determine whether to accept the petition for further action, the steelworkers said.
That would make Oct. 24 the latest date for a decision, or 10 days before the Nov. 2 congressional elections in which President Barack Obama's fellow Democrats are battling to keep control of both chambers of Congress.
The steelworkers' union was the driving force behind Obama's decision last year to slap duties on tires from China to stop a surge they said they threatened U.S. job losses.
They have also joined with U.S. steel, paper and aluminum manufacturers to bring other trade cases against China.
Obama has identified the clean energy sector as an engine for future U.S. economic growth, and has hoped to tap into the huge market in China to help fuel that.
U.S. Commerce Secretary Gary Locke in May led nearly two dozen U.S. companies on a clean energy trade mission to China. (Reporting by Doug Palmer; Editing by Peter Cooney)