WASHINGTON, Sept. 24 (Xinhua) -- The United Steelworkers (USW) union has confirmed it has joined three U.S. companies to file cases for anti-dumping and anti-subsidy duties against certain types of coated paper imported from China and Indonesia.

    The trade union was behind the recent U.S. decision to restrict tire imports from China, a move which has aroused widespread concerns over growing U.S. protectionism when the world is fighting the ongoing financial crisis and economic downturn.

    According to a statement posted on the USW website, the petitions against coated paper imports were filed on Wednesday at the U.S. Department of Commerce and the U.S. International Trade Commission (ITC) in Washington D.C.

    The three U.S. companies involved in the case are New Page Corp., Appleton Coated LLC and Sappi Fine Paper North America.

    The paper products covered by the petitions include coated paper used in high-quality writing, printing, and other applications. The cases are expected to take about a year to complete, with an ITC preliminary determination by mid-November.

    The Pittsburgh-based USW represents some 850,000 workers in a number of U.S. industries, including metals, mining, pulp and paper, rubber and chemicals.

    U.S. President Barack Obama decided earlier this month to impose punitive tariffs on all car and light truck tires from China for three years, a move denounced by China as an "act of trade protectionism."

    The Chinese government voiced its strong opposition to the punitive tariffs.

    "China strongly opposes the serious act of trade protectionism by the U.S. side," which not only breached the World Trade Organization (WTO) rules but also broke the U.S. pledges made at the April G20 summit in London, Commerce Department spokesman Yao Jian has said.

    China reserved its right to file a complaint with the WTO against the U.S. tariffs, he added.

    On Sept. 9, U.S. Department of Commerce issued a preliminary decision to impose duties ranging from 10.9 percent to 30.6 percent on steel pipe imports from China used to transport oil. The case was also brought by the USW, together with U.S. Steel, Maverick Tube Corp, and other manufacturers.

    China expressed strong dissatisfaction and resolute opposition to the decision.

    "This does not comply with WTO agreements on subsidies. The U.S. used an incorrect method to define and calculate the subsidies, which has resulted in an artificially high subsidy rate, hurting Chinese firms' interests," said Yao in a statement.