A U.S. trade panel gave final approval Wednesday to duties ranging from about 10 to 16 per cent on Chinese-made steel pipe in the biggest U.S. trade case to date against China.

The U.S. International Trade Commission voted 6-0 in favour of the duties set by the U.S. Commerce Department to offset Chinese government subsidies.

The United States imported $2.74-billion of the “oil country tubular goods” from China in 2008, more than triple the previous year, as a surge in oil prices led to increased demand for the oil well pipe.

The vote caps a year of U.S.-China trade friction.

U.S. companies and unions brought about a dozen trade cases against China in 2009, alleging government subsidies and unfair pricing practices.

President Barack Obama also angered Beijing in September by slapping a 35-per-cent duty on imports of about $1.85-billion of Chinese-made tires in response to what the ITC said was a market-disrupting surge.

China, in response, has accused the United States of protectionism, filed a complaint against the tires decision at the World Trade Organization and began a probe into whether U.S.-made autos were being “dumped” in China at unfairly low prices.

The United Steelworkers union, which was the driving force behind the tires case, joined with Maverick Tube Corp, United States Steel Corp and other U.S. manufacturers in asking for import duties on Chinese-made pipe.

The vote Wednesday clears the way for the U.S. Commerce Department to impose final countervailing duties ranging from 10.36 per cent to 15.78 per cent on the pipe to offset Chinese government subsidies, as announced on Nov. 24.

The Commerce Department has also announced preliminary antidumping duties ranging up to 99 per cent on the pipe and is expected to announce its final decision on the size of those additional duties in early April.

That would set the stage for a second ITC vote, expected in May, on whether to allow those additional duties.