Garuda Indonesia has disclosed its intent to purchase 30 Boeing 787-9s and up to 30 more 737 Max 8s.
Chief executive Arif Wibowo says the agreement is part of the airline's "revitalisation programme".
The Indonesian flag carrier has also reconfirmed an intent, disclosed in October 2014, to purchase 50 737 Max 8s.
With a fuselage stretched by 6m (20ft) over the 787-8, the -9 can fly up to 40 more passengers an additional 450nm (830km) with the same environmental performance, says Boeing.
Flightglobal's Ascend Fleets database lists 89 Boeing aircraft in Garuda's current fleet: 81 737s, two 747s and six 777s. The SkyTeam member serves 76 destinations.
In earlier versions of this story, an aircraft designation was miskeyed and an engine reference appeared out of sequence