The US government will investigate charges against import of oil well drill pipe from Chinese companies, said the Commerce Department on Thursday.

The case, which was filed by the United Steelworkers union and a group of companies from Texas and Illinois, is the first US trade probe of this year against China after about a dozen in 2009.

The petitioners have asked for anti-dumping duties ranging from 429 percent to 496 percent.

They also want additional countervailing duties to offset alleged government subsidies, the Commerce Department said.

The investigation covers heavyweight drill pipe and drill collars of iron or steel used to drill oil wells.

The Commerce Department said that the United States imported $194.6 million worth of the drill pipe from China in 2008, up from $107.1 million in 2006.

In this probe case, the US International Trade Commission has to decide by mid-February whether there is a reasonable indication that US companies have been injured or threatened with injury by the imports.

If that hurdle is cleared, the Commerce Department is expected to announce preliminary countervailing duties in March and preliminary anti-dumping duties in June.

The new case followed a series of trade restrictions the United States had imposed on imports from China.

"We are certainly not out of the woods on protectionism," Pascal Lamy, the World Trade Organization's director-general said on Thursday.

"The fundamental reason there is a protectionist impulse has to do with the job market. We know that unemployment will remain high this year, maybe even next year," Lamy said.

The United Steelworkers union has been a driving force behind many of the trade cases against China, which it accuses of causing Americans to lose jobs with competitive prices.

Economists warned that the protectionist moves by the Obama administration will ultimately hurt the US-China trade relations as well as the fragile global economic recovery.