China’s Comac scored four new orders for its C919 airliner at the Beijing Aviation Expo on Tuesday.

China Nuclear E&C Group signed a firm order for 20 of the narrowbodies and options on another 20, while Aviation Industry Corporation of China (AVIC) International Leasing and Huabao Finance and Leasing each placed firm orders for 15 and options for 15. Agricultural Bank of China (ABC) Leasing signed a firm deal for 20 aircraft and placed an option for 10 C919s, making it the biggest customer for the airplane to date. ABC has now placed orders for 75 aircraft.

The new deals raise the total order count for the C919 to 730 from 27 customers, mostly Chinese firms. It also marks the first contract signing for the model since it made its debut flight on May 5.

In late August, C919 launch customer China Eastern sent engineers to evaluate the cockpit, avionics and human-machine interface of the C919 at Comac’s Shanghai plant. By mid-August Comac had established a cockpit evaluation committee and the Civil Aviation Administration of China (CAAC) and China Eastern established an aircraft airworthiness certification center to ensure design “optimization” of the C919’s cockpit.

Comac also noted that it aims to produce six test aircraft and fly the second C919 by the end of this year.