Auckland Airport is braced for tomorrow's final report from the Commerce Commission on pricing, saying that it has ''tried to live in the spirit of the regime''.

The airport company's chief executive Adrian Littlewood said the company had made what it thought was a ''very strong'' submission last year but the commission in its draft report said the company's profits during the current pricing period may be too high.

The commission said the difference in target returns above its own midpoint could result in customers paying an additional 61c per flight over the next five years and Auckland Airport earning up to an additional $47 million in profits after tax.

There is light-handed regulation of parts of the airport's revenue, including income from the airfield, terminal activities and aircraft and freight activities.


Littlewood told shareholders at the company's annual meeting that setting prices was not an exact science and it had responded to the commission's initial report with expert evidence and more information.

The company had asked the commission to consider how ''headline'' figures in the final report would be used by the media.

''This regime has been in place since 2008 and it is the third time we've set price based on what we think is the right thing for our customers, shareholders and the travelling public.''

Airlines and airports are often at loggerheads over pricing. Airlines don't like paying for facilities years in advance and argue that the regulatory regime leaves little room to push back on prices the airport imposes. Airports say they need income certainty to plan for infrastructure projects that can stretch out decades in advance.

The 20 million passengers who use the international and domestic terminals each year pay an average of $15.44 (to increase to $16.10) to the airport for aeronautical services – including check-in facilities, passenger terminal services, landing charges, and aircraft parking.

There are further government agency charges built into airfares on top of this.

At its meeting, the airport confirmed guidance that in the 2019 financial year underlying profit would be between $265m and $275m, up on this past year's figure of $263.1m.

The company's five-year average total shareholder return - based on dividends and share price appreciation - was 20.7 per cent.


But to fund $2 billion in infrastructure work in the current five-year period, returns in the future would ''probably look a bit flatter than it has in the past little while,'' Littlewood said.

The sale of its 24.6 per cent stake in North Queensland Airports had made capital equity raising less likely but the company's debt would grow and extend.

One major and complex phase of the airport rebuild had just been completed. The departure area has been largely rebuilt with new security screening facilities, more public lounge space and a more shops.

Littlewood said work would begin soon on a new international arrivals area at the north end of the existing terminal. Work should be less disruptive than in the departures area as it could more easily be sectioned off as it was largely in a carpark area.