Bombardier has won a 719 million US dollars (£528.9 million) order for 15 new jets from American Airlines.
The purchase agreement also includes options on an additional 15 CRJ900 aircraft.
Parts of the planes including their metallic central fuselage are made in Northern Ireland.
Fred Cromer, president of Bombardier Commercial Aircraft, said: "We are pleased with American's continued confidence in Bombardier and the CRJ900 aircraft.
"This order is a testament to the tremendous value that the CRJ Series provides to airlines in the North American regional market.
"With its outstanding economics and new cabin design, the CRJ900 continues to offer unique revenue growth opportunities, while delivering the most modern regional jet cabin features in line with today's trends and requirements."
The Canadian-owned company with a major base in East Belfast recently won its US trade war with rival manufacturer Boeing over the unrelated C-Series aircraft.