FILE PHOTO: An Airbus A320neo aircraft and a Bombardier CSeries aircraft are pictured during a news conference to announce a partnership between Airbus and Bombardier on the C Series aircraft programme, in Colomiers near Toulouse, France, October 17, 2017. Picture taken October 17, 2017. REUTERS/Regis Duvignau/File Photo

MONTREAL (Reuters) - The International Trade Commission (ITC) has postponed to Friday a decision on whether duties should be imposed on American sales of Canadian plane-and-trainmaker Bombardier Inc's BBDb.TO largest jet, the U.S. agency said on Wednesday.

The ITC moved the date of the ruling from Thursday to Friday because of the recent U.S. government shutdown, a spokeswoman for the agency wrote by email.

The ITC, which oversees U.S. trade remedy laws, will decide whether to support a U.S. Commerce Department recommendation to impose a duty of nearly 300 percent on sales of Bombardier’s 110-to-130-seat CSeries to American carriers.

The case follows a petition by Boeing Co BA.N, the world's largest maker of jetliners, which said its business was hurt because Bombardier received illegal government subsidies and dumped the CSeries in the United States through the 2016 sale of 75 jets at "absurdly low prices" to Delta Air Lines DAL.N.

Bombardier, which contests Boeing's claim, made a last-minute request on Tuesday for the ITC to consider Brazilian rival Embraer SA's EMBR3.SA new E190-E2 as a competitor in the 100-to-150-seat market because of recent improvements to the new plane’s range.

On Wednesday, the Canadian planemaker’s request was denied, Bombardier spokesman Mike Nadolski said.

The ITC considered only 100-to-150-seat jets with a range of 2,900 nautical miles or more as competitors to Boeing’s 737 narrowbodies. While the CSeries was included as a competitor, the E190-E2, which will enter service this year and has around 100 seats, was excluded because it had a shorter range.