SAN FRANCISCO, Jan. 26 (Xinhua) -- U.S. aerospace leader Boeing company Friday expressed disappointment over a decision of a U.S. trade regulator that favors its Canadian rival in a trade dispute.

The U.S. International Trade Commission (ITC) voted on Friday that Canada's aircraft maker Bombardier did not harm Boeing and dropped a U.S. Commerce Department recommendation to slap a near 300-percent duty on sales of Bombardier's 110-to-130-seat C Series jets for five years.

Boeing said in a statement that it's disappointed that the ITC "did not recognize the harm that Boeing has suffered from the billions of dollars in illegal government subsidies that the Department of Commerce found Bombardier received."

Boeing accused Bombardier of selling its new C Series airliner to Delta Air Lines in the U.S. small single-aisle airplane market at "absurdly low prices" in violation of U.S. trade rules.

"We are feeling the effects of those unfair business practices in the market every day," it said.

The U.S. aircraft giant vowed to continue its fight against Bombardier's business practices, which it said "continue to harm American workers and the aerospace industry they support."

"Global trade only works if everyone adheres to the rules we have all agreed to," it said in the statement.