''That is always possible - they are a Star Alliance carrier with Air New Zealand and could co-ordinate there,'' said Littlewood.
He said all major North American carriers had consolidated, become stronger, and were looking to expand. New Zealand was already benefiting from United Airlines' decision to resume year-round flights from San Francisco later this year, and American Airlines would be more likely to commit to more flying across the Pacific if a joint venture deal with Qantas is approved.
''They're in a much more profitable and healthy state and when they're looking for growth, they are not necessarily going to get that same growth out of American markets so they are looking further afield,'' he said.
''The next hope will be American Airlines, who tell us that the LA flight performs very well in the summer - it's just getting it locked in to year-round.''
The airport's general manager of aeronautical and commercial, Scott Tasker, said it aimed to ensure that airlines operating through Auckland were sustainable and profitable.
He said that performance was helped by new, next-generation aircraft such as Boeing 787 Dreamliners and Airbus A350s that were much more efficient than the aircraft they replaced.
The new planes were ''transformational'' and now made up about 20 per cent of capacity into Auckland, up from 1 per cent in 2014.
The current generation of aircraft had a cost per seat mile that was 20-30 per cent less than the planes they replaced.
"What we will see is more and more of these aircraft coming into airlines' fleets and that will be supportive of growth. On longer flights that is really important because it de-risks for any airline launching to a far flung place like New Zealand.''
Although oil prices are rising, airlines had also benefited from relatively low fuel prices in the past two years.
Changes are under way on the Tasman, as Air New Zealand and Virgin Australia prepare to part ways when their alliance ends in October. Emirates has stopped flying to Australia from Auckland, but will start services to Dubai via Bali in June. Qantas is also putting on more capacity, with bigger A330 aircraft across the Tasman.
Air New Zealand will use the latest model Dreamliner - unaffected by the current alert over some Rolls-Royce engines - on its new Chicago route in November.