BEIJING — China has decided to renew anti-dumping duties on imports of optical fiber from the United States and the European Union for another five years as old taxes expired a year ago.

If tariffs are halted, US and EU producers, still confronted with huge idle capacity and sluggish domestic sectors, are very likely to boost their exports again, which will cause damage to China’s optical fiber market, the Ministry of Commerce said on April 21 in a statement.

Previous tax rates will be maintained, ranging from 4.7 percent to 29.1 percent based on the dumping margin.

The new duties will become effective on April 22.

China is the world’s largest and fastest-growing market for dispersion unshifted single-mode optical fiber, accounting for more than 60 percent of global demand.

The optical fiber affected is largely used in the telecommunications industry.