China is planning to impose antidumping tariffs on imports from the U.S., Europe and other markets of a chemical used to make nylon, a person familiar with the situation said Friday, in the latest sign of trade tension amid the global economic slump.

China's Ministry of Commerce is expected to announce soon a final ruling on an investigation into imports of the chemical, adipic acid. The ruling, to take effect Monday, will say that foreign companies are guilty of dumping the organic compound -- or selling it below market prices -- in China and will order antidumping duties of 5% to 35% for five years, the person said.

A spokesman for the Commerce Ministry said he hadn't been informed of any final decision in the case.

Word of the ruling comes a day after officials from the U.S. and China concluded trade talks by agreeing to reduce trade barriers in sectors ranging from agriculture to technology to travel. But disputes in other areas have been growing.

In September, Washington slapped punitive tariffs on imports of Chinese-made tires, which had been surging. China quickly responded by saying it was starting antidumping procedures against U.S. exporters into China of chicken and auto products. In mid-October, China moved to impose antidumping duties of as much as 36% on certain nylon imports from the U.S., European Union, Russia and Taiwan.

The tit-for-tat has so far been relatively restrained, and this week's concessions at the U.S.-China talks are an indication that major trading nations remain committed to trying to resolve trade differences. Still, many analysts think antidumping cases and other trade disputes are likely to increase given continued high unemployment in major exporting economies.

Details about China's antidumping ruling on adipic acid weren't available. The organic compound is used primarily to manufacture nylon, but doesn't appear to have been covered by China's earlier nylon-related decision.

A preliminary judgment on the adipic acid case in June, posted on the Commerce Ministry's Web site, suggested tariffs of 16.8% to 35.4% on imports from the U.S., varying by company. It listed tariffs of 11.3% to 30.3% on imports from the European Union, and 6% to 16.7% on imports from South Korea. It is unclear if those rates will apply in the final ruling.

The total value of adipic acid sales to China couldn't be ascertained. U.S. exports of all organic chemicals to China totaled $2.08 billion in 2008, compared with overall U.S. exports to China of $69.7 billion, according to U.S. government figures.