International Airlines Group is exercising options on eight Airbus A350-900 and will also obtain eight A330-200s for Spanish carrier Iberia.
They will be delivered from 2015-20, says IAG.
The aircraft will be used to replace 16 Airbus A340s within the airline’s long-haul fleet.
IAG had already secured commercial terms for the A350s under a broader long-haul order disclosed last year.
It has not decided the source for the A330s. They will either be taken through conversion of previous options or taken from the operating lease sector.
IAG says this decision will depend on “financial and delivery terms”.
Chief executive Willie Walsh says the decision follows Iberia’s “significant steps” in restructuring its operations.
“These orders demonstrate our commitment to make Iberia competitive,” he adds.
“Retaining an all-Airbus long-haul fleet will also generate cost savings in maintenance and crewing.”
While the A350s will be powered by Rolls-Royce Trent XWB engines, no engine selection has been given for the A330s, although Iberia’s current A330 fleet is fitted with General Electric CF6s.