IAG's new long-haul budget airline, Level, is ordering three more Airbus A330-200s for introduction to its operation next year.
The twinjets are being taken through the conversion into firm orders of IAG options on the twinjets.
IAG had already indicated plans to expand the fleet of two A330s to five aircraft for 2018, although the company had not confirmed the type or the source.
Level is based in Barcelona, and commenced transatlantic operations in June. IAG has signalled that the carrier could expand its service to other European cities.
"Long-haul flights are now available to many people for the first time," says IAG chief Willie Walsh. "We're extremely pleased with the customer response in all of Level's markets."
He says the extra aircraft will "enable it to expand", without elaborating.
Airbus has confirmed the decision to acquire additional A330-200s. Level's current A330s are fitted with General Electric CF6 engines.