The number of aircraft owned and managed by Irish lessor Avolon fell by 5 per cent to 553 in the first quarter from 570 a year earlier.
In an update to investors, the leasing company said it had total orders and commitments for 398 new aircraft in the quarter, versus 333 for the same three months in 2018.
The number of airline customers Avolon has rose to 156 from 150 over the same period.
New figures show the company delivered 12 new aircraft to nine customers and transitioned four aircraft to follow-on lessees.
Overall the company sold 20 aircraft during the quarter, which includes the sale of 10 regional planes.
The Irish Times reported this week that Hong Kong developer CK Asset Holdings is open to bidding for HNA's stake in Avolon.
The aircraft lessor last month increased debt to $500 million (€446 million) from a previously guided $300 million (€267 million).