Aircraft giant Boeing will not appeal a ruling by the U.S. International Trade Commission that allows its Canadian rival Bombardier to sell its newest commercial jets without heavy duties.

Boeing launched a trade case with the independent International Trade Commission last April, arguing that governments in Canada and Britain subsidized development of Bombardier's C Series commercial jets and allowed the Montreal-based company to sell it at unfairly low prices.

But in a surprise decision in January, the ITC voted unanimously in favour of Bombardier, saying Chicago-based Boeing didn't suffer harm from prospective imports of C Series planes.

That decision eliminated nearly 300 per cent in duties imposed by the U.S. Department of Commerce.

A Boeing spokesperson confirmed the decision not to appeal Thursday night, but declined to elaborate.

Last month, the Canadian government said Boeing was approved to participate in an upcoming competition to replace Canada's CF-18s, but the company hadn't announced a decision on whether it will actually bid.