The Commercial Aircraft Corp. of China (COMAC) signed contracts with two leasing companies for a total of 60 ARJ21 regional jets.

Shanghai-based SPDB Financial Leasing ordered 15 aircraft and took options on 15 more.

The contract, signed Nov. 6 at the Zhuhai Air Show in China, brings orders for the ARJ21 to 528, COMAC said in a statement. The state-run company typically includes options in contract totals.

The intended operators of the aircraft were not disclosed.

SPDB is owned by COMAC, Shanghai Pudong Development Bank and Shanghai International Group.

AVIC International Leasing Co., meanwhile, joined with Tianju Airlines to sign a framework agreement for 30 ARJ21s, but did not explicitly say an order had been placed. Tianju has not yet received an air operator’s certificate, but the company’s involvement in the contract suggests the airline is the intended operator of the aircraft.

Eight ARJ21s are in operation, COMAC said. The regional jet seats 90 passengers in an all-economy arrangement. Deliveries began in 2015 to COMAC subsidiary Chengdu Airlines. The manufacturer has lined up Chinese regional carrier Genghis Khan Airlines and LCC Urumqi Air as the next operators.

COMAC is working on improvements to the ARJ21, aiming especially to reduce the weight of the secondary structure. Changing the primary structure would be too costly, an industry source said.

Bradley Perrett,