Airways New Zealand has expressed surprise at suggestions it is taking advantage of its monopoly position to bump up charges to airlines.
The company, which handles air traffic across the country and manages air traffic control towers, says it held off on non-vital infrastructure investment during the global financial crisis to help airlines.
Now Airways is putting up its prices by nearly 16% over the next three years.
On Tuesdaym International Air Transport Association chief executive Tony Tyler criticised the rise in prices saying it was a heavy handed decision by an infrastructure provider with a monopoly.
Mr Tyler said the price increases will create big problems for airlines.
Airways New Zealand chief financial officer Mark Loveard said the majority of the increase is required to fund the replacement of infrastructure.
He said the company proposed to its customers an investment programme over the next three years of $97 million - $88 million of which was unequivocally approved.
He said overall there was a lot of support by customers for the company's capital programme.