Reuters reported in July that Chinese financial firms had placed large orders at the Farnborough Airshow without initially being identified, including Avolon's preliminary order for 100 jets that has now been finalised and made public.
Airbus's then sales chief Eric Schulz said at the time some Asian buyers were asking not to be named due to sensitivities over trade tensions between China and the United States.
Although Europe's Airbus has not reaped the benefit some had predicted from the standoff - with its own direct sale of jets to China blocked for almost a year - finance sources say China-linked firms have generally been keeping a low profile in order not to be caught on the wrong side of the shifting dispute.
Avolon was not immediately available for comment.
In a statement, China's Bohai Leasing Co Ltd, controlled by conglomerate HNA Group, said its Dublin-based Avolon Aerospace Leasing unit had signed a firm deal to buy 75 Airbus A320neo jets and 25 of the larger A321neos.
The aircraft will be delivered between 2023 and 2026.
The deal underscores Avolon's continued expansion despite financial difficulties faced by the HNA group of companies.
Avolon has been forced to put distance between itself and its ultimate parent, telling investors earlier this year that it would be impossible to milk the aircraft leasing firm for cash to prop up the cash-pinched Chinese conglomerate.
In August, Japanese financial services group Orix Corp struck a $2.2 billion deal to buy a 30 percent stake in Avolon Holdings as HNA Group trimmed holdings in core assets.
Avolon's founder and chief executive, Domhnal Slattery, said in Friday's statement that the scale of the Airbus order reflected the "long-term commitment and strategic perspective of our shareholders."
Asked last week whether HNA's Bohai intended to sell more shares in Avolon or whether Avolon would seek to open its capital further, Slattery told Reuters "not at the moment".
Avolon is expanding to meet what it sees as robust demand for aircraft despite concerns among some analysts that an extended commercial aviation cycle is softening.
In November last year, Avolon placed an order for 75 competing Boeing 737 MAX airplanes worth $8.7 billion at list prices and said it may order 20 more.
Last week Avolon facilitated the first delivery of an upgraded Airbus A330neo airliner to TAP Portugal.
(Writing by Jamie Freed, Tim Hepher; Editing by Muralikumar Anantharaman and Adrian Croft)
By Stella Qiu and Tim Hepher