Air China is ordering 35 of the Chinese-built Comac ARJ21-700 twinjet, under a deal it values at $1.33 billion.

Delivery of the aircraft is scheduled to take place in stages from 2020 to 2024, the flag carrier states.

Air China adds that it has negotiated a "large price concession" which means the actual price will be lower that the catalogue figure.

The aircraft will be used to expand the main fleet or those of its subsidiaries, although it has not specified which operators will use the ARJ21s.

It says the transaction, approved during aboard meeting, will not have any "significant impact" on its cash flow or business operations.

Acquisition of the aircraft will increase the overall group capacity by just over 1%, it adds.