Belfast planemaker Bombardier Aerospace has received a letter of intent for the purchase of 12 planes in a deal which could be worth more than £340m if completed.
The company's Belfast operation is responsible for the design and manufacture of the centre fuselage, engine nacelles and wing components for the 88-seat CRJ900 NextGen regional jets.
The announcement was made on the opening day of the Singapore Air Show, just hours after the firm revealed that three C-Series aircraft, the wings of which are made in Belfast, had been sold to another unnamed customer in a contract worth £139m.
In total, Bombardier has recorded firm orders for 1,812 CRJ Series aircraft, including 339 CRJ900 and CRJ900 NextGen aircraft.
Worldwide, CRJ Series aircraft are in service with more than 60 airlines and more than 30 customers operate corporate variants of the aircraft, which are operating in over 50 countries on six continents.
The models have transported more than 1.4bn passengers and have logged more than 38m flight hours and over 32m takeoffs and landings.
Bombardier says that on average, a CRJ aircraft takes off every 10 seconds somewhere in the world.
Mike Arcamone, president of Bombardier Commercial Aircraft, said that recent enhancements to the aircraft allow it to offer up to 5.5% lower fuel consumption.
"Bombardier set the performance benchmark for aircraft in this category and we're constantly moving that benchmark forward – which is a big reason for its success," he said.
Bombardier is one of nine Northern Ireland companies taking part in Singapore Air Show, Asia's largest aviation and aerospace event.
The businesses are part of a 30-strong contingent from around the United Kingdom and Ireland on the first joint trade mission between Stormont, Westminster and Dublin.
Securing export orders is expected to be the main focus on the companies on the trip, but there's also the possibility of securing inward investment.