The Commerce Department began closing a chapter in a protracted trade conflict with China over solar equipment Tuesday, approving a collection of steep tariffs on imports from China and Taiwan.

The decision, intended to close a loophole that had allowed Chinese manufacturers to avoid tariffs imposed in an earlier ruling by using cells — a major module component — made in Taiwan, found that the companies were selling products below the cost of manufacture and that the Chinese companies were benefiting from unfair subsidies from their government.

The department announced anti-dumping duties of 26.71 percent to 78.42 percent on imports of most solar panels made in China, and rates of 11.45 percent to 27.55 percent on imports of solar cells made in Taiwan. In addition, the department announced anti-subsidy duties of 27.64 percent to 49.79 percent for Chinese modules.

“These remedies come just in time to enable the domestic industry to return to conditions of fair trade,” said Mukesh Dulani, president of SolarWorld Americas. “The tariffs and scope set the stage for companies to create new jobs and build or expand factories on U.S. soil.”