The United States Wednesday accused China of illegally subsidizing the production of wind-power equipment and asked for talks at the World Trade Organization, the first step in filing a trade case.

"Import substitution subsidies are particularly harmful and inherently trade distorting, which is why they are expressly prohibited under WTO rules," U.S. Trade Representative Ron Kirk said in a statement.

"These subsidies effectively operate as a barrier to U.S. exports to China."

USTR made the announcement in response to a petition filed in September by the United Steelworkers (USW). It comes about a month before a visit by Chinese President Hu Jintao to Washington for talks with President Barack Obama.

The industrial union accused Beijing of a long list of subsidies and other trade-distorting policies to favor the manufacture of clean energy technologies in China, at the expense of the United States and other producers.

The steelworkers' so-called "section 301" petition included a complaint about China's restrictions on rare earth minerals used in production of wind turbines, electric vehicles, solar cells and energy efficient lighting.
USTR announced no decision on that issue.

"We will continue to work closely with the USW and other stakeholders in the months ahead on the remaining allegations. If we are able to develop sufficient evidence to support those allegations and they can be effectively addressed through WTO litigation, we will pursue the enforcement of our rights at the WTO independently of section 301," Kirk said.