Russian airframer Irkut has signed a state contract with the Government to carry out the next stage of research and design work on the proposed MS-21 twin-jet.
Under the pact, Irkut is to receive Rb24 billion ($820 million) from the state budget for the work, which is to be completed by December 2012.
The firm is steering the development of a three-member family of medium-range aircraft accommodating 150, 180 and 210 passengers.
MS-21 programme director Sergei Galperin estimates its total costs at Rb190 billion, of which 40% is funded by the state.
Irkut president Oleg Demchenko says the launch customer, Crecom Burj, which has placed a firm order for 50 aircraft, is to make an advance payment shortly.
He expects Aeroflot to conclude a binding agreement, covering the supply of a further 50 MS-21s in March.