China launches WTO challenge over U.S. anti-subsidy tariffs GENEVA (Reuters) - China filed a complaint at the World Trade Organization on Monday to challenge a new U.S. law on "countervailing duties," or tariffs intended to combat export-promoting subsidies. The complaint, filed hours after the United States said it would launch a wide-ranging trade complaint against China's support for car exports, potentially affects close to 30 products that have previously been targeted by U.S. duties, a trade official familiar with the case said. In a brief statement, the WTO said the products included steel, tires, magnets, chemicals, kitchen appliances, wood flooring and wind towers. Reporting by Tom Miles; Editing by Toby Chopra