The U.S. Department of Commerce is adding nearly 80 per cent in preliminary anti-dumping duties on exports of Bombardier's CSeries commercial jet.
The Montreal-based aircraft manufacturer's 100- to 150-seat plane faces a total tariff of almost 300 per cent when combined with last week's almost 220 per cent countervailing duties.
The U.S. government again sided Thursday with Chicago-based aircraft giant Boeing Co. in its petition against the new CSeries.
Bombardier didn't immediately respond to the latest duty announcement, but last week said it was confident that the ``absurd'' and unfounded tariffs will be reversed in final decisions in the coming months.
Bombardier says that ultimately Boeing can't justify its claim of being harmed since it doesn't make a plane the size of the CS100.
A protracted battle could then ensue if either side appeals the case to the U.S. Court of International Trade, brings it before NAFTA dispute bodies, or even take the matter to the World Trade Organization.