Boeing is firing back at two of its biggest rivals after Bombardier handed control of its CSeries program to Airbus.

"This looks like a questionable deal between two heavily state-subsidized competitors to skirt the U.S. government findings," Boeing said in a tweet late Monday. "Everyone should play by the same rules for free and fair trade to work."

Boeing has been locked in a bitter trade dispute with Bombardier over claims the CSeries jet is being sold into the United States at "absurdly" low prices.

The U.S. Department of Commerce recently announced preliminary duties totaling almost 300 per cent on CSeries imports into the States. Those levies are not final, and still subject to a final determination by Commerce and an eventual ruling by the U.S. International Trade Commission.

Bombardier has criticized the duties as being an "egregious overreach" and "divorced from reality."

U.S. Commerce Secretary Wilbur Ross declined to comment on Bombardier’s deal with CSeries on Tuesday, saying by email his office doesn’t “know enough about this new development to comment on its potential impact” on the government’s review of Boeing’s claims.