Hainan Airlines unit Urumqi Air is set to acquire 40 Comac ARJ21-700 regional jets in a deal worth $1.5 billion.
The airline signalled its intention to sign for the aircraft in a stock market statement disclosed on 11 November. The deal still awaits shareholder approval.
The regional jets would be delivered between 2025 and 2032.
Urumqi operates 18 Boeing 737-800s. It has previously been linked with a order for ARJ21s, but the status of these aircraft is not clear.