The Commerce Commission says Auckland International Airport Ltd is not making excessive profits on what it charges customers and airlines.
The commission has released a draft report on the effectiveness of its information disclosure regime, which requires airports to provide five year financial forecasts and what they intend to charge over that period, as well as other information for scrutiny.
It's found that the requirement has had a positive impact on the way Auckland International Airport sets its prices.
The commission looks at the revenue Auckland Airport intends to earn through charges to customers and airlines and calculates the airport's return compared to the assets used to provide the services.
Deputy chair Sue Begg said the airport company has improved the way it sets prices to collect revenue for different services.
She said the draft report findings contrast with the commission's conclusion on Wellington Airport which found it was making excessive returns and that the regulation had not been effective for it, which she says is down to businesses responding to regulation in different ways.
The final report is expected to be completed by the end of July.
Shares in Auckland International Airport were up by 4 cents to $3.03 each.