GENEVA An appeals panel of the World Trade Organization has upheld a ruling that China unfairly imposed import tariffs on a high-technology U.S. steel product.

In a ruling Thursday, the WTO appeals panel said China was wrong in the way it put duties on U.S.-made grain-oriented flat-rolled electrical steel. China had argued that the tariffs were legitimate because U.S. Buy American provisions and state government procurement laws amount to a subsidy for the products, which are used in items such as transformers.

The ruling backed an earlier WTO finding in June based on a 2010 U.S. complaint.

Countries can impose punitive tariffs to offset damage from subsidies, but the U.S. contends China used the measures in a way that hurts American exporters.