The U.S. Commerce Department on Wednesday issued a final ruling in favor of an antidumping complaint filed by the U.S. steel industry against Japanese-made steel pipes for use in gas and oil pipelines.

If the ruling is upheld in a final decision by the U.S. International Trade Commission, scheduled for late October, antidumping duties corresponding to dumping margins will be levied against welded large-diameter line pipes from Japan.

In Wednesday's ruling, the Commerce Department set the dumping margins at 30.8 percent on the imports from Nippon Steel Corp., Kawasaki Steel Corp. and other Japanese steelmakers.

The rates are unchanged from those announced in June by the department in its preliminary ruling that the Japanese companies are selling the steel pipes in the U.S. below fair market value.

The ITC issued a preliminary decision in February that imports of the steel pipes from Japan are adversely affecting the U.S. steel industry.

Three U.S. steel makers -- Berg Steel Pipe Corp. in Florida, American Cast Iron Pipe Co. in Alabama and Stupp Corp. in Louisiana -- filed the antidumping petition in January.

The petition over the steel pipes was the 13th lodged by the U.S. steel industry against Japanese-made steel products since the so-called steel crisis hit U.S. steelmakers in the wake of the 1997-1998 Asian financial crisis.

Twelve complaints have already been settled.

Washington has imposed punitive duties on eight categories of steel products, including hot-rolled steel sheets and stainless steel sheets, while dismissing charges against four categories, such as cold-roll steel sheets.