Airbus is still waiting for European certification for its A320 enhancement to increase maximum take-off weight to 78t.
But the airframer is expecting imminent approval for International Aero Engines V2500-powered aircraft, with CFM International CFM56 variants following shortly.
The enhancement, for which US carrier JetBlue will be the first customer, takes advantage of the type's load-alleviation function to improve the MTOW by about 1t.
Airbus says the modification, which requires a software upgrade to the elevator and aileron control computer, can be applied to aircraft later than MSN1903, owing to structural reinforcement of the horizontal stabiliser.
Aircraft MSN1903 is a 2002 example currently in service with Lan Argentina.
Airbus A320-family director of product marketing Stuart Mann, speaking during a briefing in Hamburg, said the European approval for the V2500-equipped variant was due "any day" and that the CFM56 clearance would come "later".