Russian lessor Ilyushin Finance has signed a firm order for 28 United Aircraft MS-21 narrowbody aircraft.
The order is for the -300 variant and includes options for another 22 of the type, said United Aircraft.
Deliveries are due to start in 2019 and continue until 2022. The order has a list price of $4 billion, said the Russian state-owned airframer.
It has pitched the 150-180 seat aircraft as a competitor to the Airbus A320 and Boeing 737 family of aircraft.