The decision was a surprise for some observers who expected the commission would side with Boeing even though they believed the company sustained no harm.
Politicians and union leaders have welcomed a ruling which stops the U.S. imposing huge 292 per cent import tariffs on planes partly made by British workers.
"He's got an independent hand on all of those", said Edward Alden, a trade policy expert at the Council on Foreign Relations.
Earlier this week, the Trump administration approved tariffs on behalf of Whirlpool (NYSE:WHR) against washing machine rivals, including Samsung and LG, and on behalf of USA solar panel companies against imported cells.
On Friday evening, following the ITC vote in Washington, Steve Turner, Unite assistant general secretary, said Bombardier's Northern Ireland workforce and its supply chain could now breathe "a huge sigh of relief" that the ITC had dismissed Boeing's complaint. And it means duties totalling almost 300 per cent imposed by the U.S. Department of Commerce on the C Series will be called off.
The decision reverses the determination made by the U.S. Department of Commerce that Bombardier should pay tariffs of almost 300% on sales of its 100- to 150-seat CS 100 and CS 300 jets.
"This clears the way for the jets being to delivered to Delta", Murray said.
Bombardier has said Boeing's case has no merit and that its actual intent is to force Bombardier out of the 100-seat market as it looks to acquire a competing maker of small jets.
The decision Friday is a significant blow to Chicago-based Boeing and gives an unexpected boost to Airbus, Boeing's rival in the commercial airline market. Boeing has projected a market for 29,000 narrow-body planes over the next 20 years, and sped up production of the 737.
Because of its displeasure over the previous CSeries rulings, the Canadian government had put on hold an all-but-completed deal to buy Boeing F/A-18 jet fighters valued at $5.2 billion.More news: Mahadayi could trigger more bandhs in Karnataka as political sparring continues
Delta's position goes a little further: at the time of the tenure, Boeing just offered second-hand Embraer 190s.
Boeing has not yet indicated whether it will lodge an appeal against the ruling.
"Today's decision is a victory for innovation, competition and rule of law", Bombardier said in a statement released shortly after the vote.
Bombardier spokesman Mike Nadolski said Tuesday that Boeing has been disingenuous by demanding the US government ignore Embraer's role in the market while trying to buy the Brazilian aerospace manufacturer.
Marcil thanked both the Canadian and Quebec governments for their support in the dispute as well as Bombardier workers.
"I'm thrilled that common sense has finally won out and that these ridiculous tariffs have been tossed", said Unifor National President Jerry Dias.
Bombardier in October past year sold a majority stake in the C Series program to Europe's Airbus SE for no cost. Airbus executives argued that moving production in that way should allow them to avoid the tariff.
Canada's main stock index rose on Friday, led by shares in Bombardier Inc (BBDb.TO), which closed up more than 15 per cent after it won an unexpected trade victory against US planemaker Boeing Co (BA.N).
"There is no joint venture".
Bombardier shares jumped more than 15% after the ruling.
Bombardier has received large sums from government administrations in the United Kingdom and Canada as part of the development of the C Series. Delta in December also selected AIrbus over Boeing for an order of up to 200 new single-aisle jets. The two companies have not announced a finalized deal yet.