By David Shepardson and Eric Beech

The U.S. Commerce Department said on Tuesday it had opened investigations into vehicle tire imports from South Korea, Taiwan, Thailand and Vietnam to determine whether the tires are being sold at less than fair value.

The department said it was also investigating whether tire producers in Vietnam were receiving unfair subsidies for passenger vehicle and light truck (PVLT) tires.

The investigations were in response to petitions filed in May by the United Steelworkers (USW) representing workers at U.S. tire plants.

"Even though demand for PVLT tires increased, domestic producers were still forced to grapple with reduced market share, falling profits and lost jobs," USW International President Tom Conway said earlier.

The union won orders on imported vehicle tires from China in 2015, and Chinese imports have since shrunk dramatically, allowing the domestic industry to invest in new capacity, the union said.

The United States imported almost $4 billion in tires from the four nations, including nearly $2 billion from Thailand and $1.2 billion from Korea, in 2019. The USW said tire imports from the four countries have risen nearly 20% since 2017, reaching 85.3 million tires.

The Commerce Department said the alleged dumping margins range from 43% to 195% for Korea, 21% to 116% for Taiwan, 106% to 217.5% for Thailand and 5% to 22% for Vietnam.

The USW represents workers at Michelin, Goodyear, Cooper, Sumitomo and Yokohama tire plants in Ohio, Arkansas, North Carolina, Kansas, Indiana, Virginia New York and Alabama.

This month, Hankook Tires urged the Commerce Department not to investigate, saying the U.S. domestic tire industry "is in robust health and growing." In a filing it said, domestic vehicle tire producers "as a whole have not been materially injured and are not threatened with material injury by reason of subject imports."

Vietnam's Ministry of Industry and Trade told Commerce its economy is "heavily dependent on light vehicles and passenger cars for transportation, logistics and travel and the PVLT tire industry is crucial for our continued economic advancement."

(Reporting by Eric Beech and David Shepardson; Editing by Mohammad Zargham and Tom Brown)