Wellington International Airport, which is co-owned by Wellington City Council and Infratil, has "excessive" earnings targets that aren't being pulled down by stricter disclosure rules, according to the Commerce Commission.
The antitrust regulator estimates the airport's pricing will achieve a return on investment of 10.18 per cent in the period between 2013 and 2017, above the hub's own 9.5 per cent target and above the 7 per cent to 8 per cent range the commission deems "reasonable".
The finding comes in the regulator's draft report to the Ministers of Commerce and Transport on how well disclosure rules are promoting regulation for the airport.
"Our draft findings are that the information disclosure regime is working well in some areas, but it is not limiting Wellington Airport's ability to extract excessive profits," deputy chair Sue Begg said in a statement. "Either figure significantly exceeds our estimate of a reasonable rate of return, which we base on our cost of capital input methodology."
Wellington Airport has been accused of price gouging in the setting of its air service charges, with national carrier Air New Zealand flagging a $200 million lift in landing fees over the coming five years.