Comac has secured commitments for 20 of its C919 narrowbody aircraft from Industrial Bank Financial Leasing Co, bringing its total order backlog to 400 aircraft.
The agreement, which was inked in Beijing on 28 October, also states that the Chinese lessor will be the launch customer of the C919 business jet variant once it is launched.
The pricing and delivery schedule of the deal were not disclosed.
Comac's chief financial officer Tian Min says the commitments shows that the C919 meets market demands, and that both foreign and local players have confidence in the product.
The C919 is pitched against the Boeing 737 and Airbus A320. In August, the Chinese airframer announced that the aircraft's first flight would be pushed back one year to the end of 2015, pointing out that the programme has not met with any major setbacks, but that it has little experience working with various domestic and foreign suppliers.
The programme has entered into the "most critical stage of engineering development" as detailed design continues. Aircraft structural data has also been distributed while parts and components manufacturing is currently "in full swing" across at least five different Chinese cities.
The commitments for the 400 aircraft on its backlog are mostly from Chinese airlines and leasing companies.