South Korea won a case at the World Trade Organization against the United States over the country slapping anti-dumping duties on steel pipes, nearly three years after lodging the complaint, a panel report showed on Wednesday.

In July 2014, the US Commerce Department levied 9.9 percent to 15.8 percent anti-dumping duties on oil country tubular goods imports from Hyundai Steel, Nexteel, Seah Steel Corp. and Husteel.

OCTG is one the fastest growing sectors in the pipelines market and South Korean producers enjoyed a boom in the North American country's oil and gas industry.

Five months later, South Korea submitted an appeal with the WTO against the tariff, arguing that the US calculation of margins for Korean products was not "reasonable" when compared to the rate of global profit margins.

The WTO dispute settlement panel sided with Seoul's claim that the US incorrectly applied the term "same general category of products" in determining for OCTG products and didn't use the actual profit data. The Korean companies exported 98 percent of their products to the United States.

"If the panel ruling is confirmed and the US complies with it, anti-dumping measures on Korean OCTG will be lifted," Seoul's trade ministry said in a release. "It would enhance the business environment for Korean companies in the US market."

The ruling will be confirmed if the two sides don't appeal within 60 days.

South Korea exported $818 million worth of OCTG to the world's largest economy in 2013, but the amount shrank to $262 million in 2015 and $271 million in 2016, the ministry said. (Yonhap)