The Commerce Commission says the current information disclosure regime has had a positive influence on Auckland International Airport's price-setting behaviour.
Commission deputy chair Sue Begg says the airport's targeted return of 8% between 2013 and 2017 is just within the regulator's estimate of acceptable returns of 7.1% to 8%.
"Auckland Airport is towards the upper end of the range, which means that we consider it will be a little bit above our assessment in normal returns, but at that level we don't think it's so high as to suggest it will be earning excessive profits."
She says estimating the cost of capital is not a precise science, so the commission has set a range where it believes the returns are acceptable.
Ms Begg says it's important to provide businesses with adequate incentives to invest and there is a margin to ensure that the return businesses are allowed is sufficient.
However, the Board of Airline Representatives New Zealand says the airport is making $72 million in excessive profits which means higher costs for its members.
The organisation's legal counsel, Kristina Cooper, says airlines are operating in a hugely competitive environment and are forced to either charge travellers more or absorb these costs and that can lead to reduced services.
