The US Army is expected to sign a contract within the next few weeks for its first two Alenia Aeronautica C-27J Spartan Joint Cargo Aircraft, with deliveries due by June 2008.
The programme's original request for proposals called for the purchase of a further four aircraft in fiscal year 2008, seven in FY2009, 15 in FY2010 and 26 in FY2011.
However, the army and US Air Force say they may buy another 24 aircraft beyond this commitment.
The initial JCA production rate means that final assembly of the C-27J will continue at Alenia's facilities near Turin, Italy until at least 2012, with the aircraft to have avionics and countermeasures equipment installed at L-3 Integrated Systems' plant in Waco, Texas.
Plans to move final assembly to a Boeing centre in Jacksonville, Florida, are dependent on reaching a sustained production rate of at least 20 aircraft a year, says L-3.