Airbus plans to announce a 150-jet A220 order from AirAsia on May 6.
Reports of the substantial agreement first emerged on May 5.
The deal represents one of the largest single commitments for the A220 program to date.
AirAsia currently operates a fleet primarily composed of larger A320-family aircraft.
The smaller A220 jets will allow the carrier to service thinner routes efficiently.
This strategic shift targets expansion into secondary markets across Asia.
The order strengthens the A220 program against competitive pressure from Embraer.