The U.S. Commerce Department on Thursday set hefty final duties on imports of glossy paper from China in a landmark case challenged by Beijing at the World Trade Organization.

The department also announced substantial final duties on imports from South Korea and Indonesia in the case filed late last year by NewPage Corp. of Dayton, Ohio, a U.S. producer of glossy paper used in art books, high-end magazines, textbooks and annual reports.

At issue in the case against China was whether it was appropriate to impose "countervailing duties" against countries still classified as non-market economies under U.S. trade law.

The Commerce Department had refrained from doing that for decades, partly on the grounds it was too difficult to determine subsidy levels in countries where the government had control over most of the economy.

But in a preliminary ruling in March, the Commerce Department said that policy no longer made sense in regard to China and announced preliminary countervailing duties of up to 20.35 percent to offset government subsidies for China's glossy paper producers.

After investigating the matter further, the department announced final countervailing duties on Thursday ranging from 7.40 to 44.25 percent on glossy paper from China.

"The United States will enforce U.S. trade laws to ensure American businesses are treated fairly. Subsidies in China keep out our exports and distort global trade flows," said David Spooner, the department's assistant secretary for import administration, in a statement.

The Commerce Department also set final countervailing duties on Thursday of 22.48 percent on glossy paper from Indonesia and zero to 1.46 percent from South Korea.

NewPage also accused the three countries of selling in the United States at below fair market value and sought additional "anti-dumping" duties to negate that practice.

Commerce agreed and set final anti-dumping duties on Thursday of 21.12 to 99.65 percent on imports from China, 8.63 percent on imports from Indonesia and up to 31.55 percent on imports from South Korea.

Beijing has complained to the WTO about the U.S. decision to impose countervailing duties while still classifying China as a non-market economy and that dispute is now working its way through the system.

But U.S. steelworkers, who hope to see the Commerce Department impose countervailing duties against Chinese steel imports, were pleased by Thursday's decision.

The Sierra Club also applauded the duties on Indonesia, which it hoped would lead to less illegal logging in that country's wildlife and plant-rich rain forests.

The U.S. International Trade Commission still has the final decision on whether the duties will remain in effect and held a hearing on the glossy paper case on Thursday.

For the duties to remain, the panel has to determined that U.S. producers have been, or could be, materially injured by the low-priced imports.

That vote is expected by the end of November.