Bombardier Inc's (BBDb.TO) aerospace business spent US$2.4 billion in the United States last year, tapping more than 800 suppliers in all but three U.S. states, according to a confidential Bombardier report seen by Reuters on Thursday.

The report shows the potential impact on the U.S. economy and companies if the Canadian company's new CSeries jetliner is effectively kept out of the U.S. market by a trade row initiated by Boeing Co (BA.N) earlier this year.

Boeing has accused Bombardier of receiving taxpayer subsidies that allowed it to sell the CSeries in the United States at prices below cost. Last week, the U.S. Department of Commerce proposed a duty of nearly 220 per cent to compensate for the subsidies, and the agency is due to issue a decision on potential additional duties for dumping later on Thursday.

The imposition of additional duties would effectively keep Bombardier out of the United States because it would make its planes too expensive to be competitive

The report said more than half of the materials Bombardier buys for the new CSeries plane come from U.S. suppliers, with the most spending in California, Connecticut, Illinois, Iowa and Kansas, the report said.

The duties, which would affect an order for 75 planes by Delta Air Lines (DAL.N), would not take effect unless approved by the U.S. International Trade Commission early next year.

Bombardier has already said that its spending supports 22,700 jobs in the United States, and it has identified major CSeries suppliers such as Connecticut-based engine maker Pratt & Whitney, a unit of United Technologies Corp (UTX.N), and Iowa-based avionics maker Rockwell Collins Inc (COL.N). United Technologies is in the process of acquiring Rockwell Collins.

The report identifies the 10 largest CSeries suppliers, including French interiors supplier Zodiac Aerospace SA (ZODC.PA), through its operations in California; Honeywell International Inc (HON.N), which makes auxiliary power units in Arizona; Spirit AeroSystems Holdings Inc (SPR.N) in Kansas; and Parker Aerospace, a unit of Parker-Hannifin Corp (PH.N) which has operations in Utah, California and Michigan.