Last month, it announced a net loss of A$244 million ($313 million) - a half-billion-dollar reverse from a net profit of $250 million in the previous 12-month period.
Byrne said although there was little detail of the transtasman plans it was logical there could be further rationalisation there.
"There's been quite a bit of capacity on that route. Any rationalisation that Emirates and Qantas do has got to be good for everyone."
Byrne said there could be fewer flights but they would be fuller.
This would not necessarily mean increased fares as airlines had realised low fares were needed to stimulate the market.
Air New Zealand said last week it had load factors of 80 per cent across the Tasman while its competitors' planes were running at 60 to 65 per cent full.
"You don't have to put prices up and you've still got pretty good competition between Air New Zealand, Qantas, Emirates and Virgin," Byrne said.
Under the deal, Qantas will fly daily A380 services from both Sydney and Melbourne to London via Dubai. Qantas shares jumped 9c late yesterday at $1.22.