An airline lobby group fears proposed changes to the way major airports value their assets will let them continue to unfairly charge many millions in extra charges.
The Commerce Commission has issued proposed new rules detailing what information Auckland, Wellington and Christchurch airports should make publicly available and how they should value their assets and calculate costs and capital spending.
The changes are part of a push for greater financial disclosure and transparency when the airports set fees.
Disappointed newer figures used
The Board of Airline Representatives says the cost information that relates to landing and passenger fees is based on solid principles that have remained largely unchanged since a price inquiry in 2002.
Executive director John Beckett says he's disappointed the commission has allowed the airports to use their 2009 asset valuations as a base figure, rather than the lower 2002 figures.
Mr Beckett says the board will continue to push for changes.
Auckland International Airport Ltd says it's still reviewing the draft, but still believes airports need the right commercial incentives to ensure the necessary infrastructure investment are made.
Opportunity to critique proposals
Commerce Commission chairman Mark Berry says affected parties now have the opportunity to critique the draft rules, and because it's an entirely new regime the commission has asked four international experts to provide their views.
The commission intends to make a final determination by the start of next year.