WASHINGTON, Feb 16 (Reuters) - The U.S. Commerce Department said on Tuesday an Australian company once owned by the world's biggest miner BHP Billiton (L:BLT) Ltd BHP.AX sold silicomanganese in the United States at a dumping margin of 12.03 percent, and a final decision on imposing duties on the imports would be made on March 28.
West Virginia-based Felman Production LLC has said large and increasing volumes of silicomanganese, an alloy additive used to make steel, from Tasmanian Electro Metallurgical Co (TEMCO) have "significantly undercut" U.S. prices.
BHP spun off the plant into a separate company, called South32 S32.AX , to shareholders in May.
The Commerce Department in September said it planned to impose preliminary duties of 11.93 percent on the goods.
In a statement on Tuesday, it said it had determined the dumping margin to be 12.03 percent. The U.S. International Trade Commission will make its final decision on March 28, it said.
The value of silicomanganese imports from Australia in 2014 was estimated at $76.9 million, it added.