The Commerce Commission says a disclosure regime is not stopping Christchurch International Airport Ltd from making excessive profits.
The commission says the airport's proposed prices over 20 years from 2012 to 2032 target an 8.9 percent return.
That's well above what it regards as an acceptable return of between 7.6 and 8.5 percent.
Deputy chair Sue Begg said the disclosure regime appears to have had little influence on the airport's conduct or performance.
But she said the airport is targetting what it considers an acceptable return for the current five year pricing period.
Ms Begg said Christchurch airport's price-setting behaviour seems to be primarily influenced by demand-related considerations, such as the Canterbury earthquakes, rather than by the disclosure regulations.
She said there is also a lack of transparency in the airport's approach to setting prices although it has signalled a commitment to improve that.
But Ms Begg said the commission is not making any recommendation on whether other regulation is needed because that's outside of the scope of the review required by the legislation.
She said the Commerce Commission report will now go to the Ministers of Transport and Commerce and it's up to the policy-makers as to what happens from here.
Call for firmer price regulation
The Board of Airline Representatives New Zealand is calling on the Government to subject airport companies to firmer price regulation.
Chief executive John Beckett says the current regime is too light-handed.
He said around the world airports are seen as monopolies and there is some form of regulation over their price setting.
Mr Beckett said in New Zealand the airports are free to set prices as they see fit, all they have to do is to disclose the information on which they set the prices.
"We believe that New Zealand should line up with the rest of the developed world and have a form of regulation over the pricing of airports in New Zealand."
Mr Beckett said his organisation is advocating to the Government a system called negotiate-arbitrate, which is already set up in the Commerce Act.
He said it would mean airports would move from information disclosure only with the freedom to set prices as they see fit, to a regime in which they would be asked to negotiate with the airlines and then failing that there would be arbitration with the Commerce Commission.
