WASHINGTON (Yonhap News) -- U.S. trade authorities on Friday announced a full-fledged investigation into allegations that major South Korean firms Samsung and LG have violated anti-dumping rules here.

"The U.S. International Trade Commission (ITC) has made affirmative determinations in its preliminary phase anti-dumping and countervailing duty investigations concerning certain large residential washers from Korea and Mexico," the agency said in a press release.

The move came after Whirlpool Corp., a Michigan-based home appliance maker, filed anti-dumping petitions regarding washing machines manufactured by Samsung and LG.

Whirlpool immediately welcomed the ITC decision.

"Whirlpool Corporation is pleased with the ITC's preliminary affirmative injury determination,” spokesperson Kristine Vernier said. “This decision by the ITC validates the actions we've taken to protect the U.S. domestic appliance industry, our 23,000 U.S. employees and the communities in which they work.”