Qatar Airways is replacing a previous order for Airbus A320neos with a revised agreement for 50 A321neos configured with a new fuselage door arrangement.
The agreement for the Airbus Cabin Flex version of the A321neo appears to settle a dispute over the Middle Eastern carrier's previous A320neo deal.
Qatar had ordered 50 A320neo-family jets in 2011 but it began cancelling individual A320neo deliveries in July last year.
The Doha-based carrier had originally intended to be the first airline to take delivery of an A320neo, but it dropped out as technical issues emerged with the Pratt & Whitney PW1100G powerplant.
Qatar cancelled four A320neo deliveries leaving it with 30 A320neos and 16 A321neos in Airbus's backlog, none of which has been delivered.
Airbus had signalled at the beginning of this year that it was working on an agreement to "upsize" the order to include more A321neos.
The airframer says Qatar has "reaffirmed" its previous order by restoring it to 50 aircraft and converting upwards to the A321neo with the Airbus Cabin Flex layout.
This layout features the overwing exits enabling the type to accommodate additional passengers. The variant can seat up to 240 depending on the interior arrangement.
Airbus has not confirmed whether Qatar Airways has switched to the rival CFM International Leap-1A powerplant – although an illustration accompanying its disclosure of the order features the Leap-powered variant.
Qatar Airways will start taking delivery of the A321neos in 2019. Airbus values the agreement at $6.35 billion at catalogue prices.