Lessor Hong Kong Aviation Capital has finalised an order for 70 Airbus A320neo-family jets, the airframer confirmed during the Farnborough air show.
The agreement covers 40 A320neo aircraft plus 30 of the larger A321neo.
Hong Kong Aviation Capital had outlined a large acquisition under a memorandum of understanding during last year's Paris air show.
That agreement would have covered 60 aircraft. But it is taking another 10 A321neos.
Hong Kong Aviation Capital chief Donal Boylan says the larger type will enable operators to "better compete where airport slots are restricted".
No engine selection has been given for the jets, nor has the airframer indicated a delivery date. Airbus says the lessor is a new customer for the aircraft.