The lawyers will seek up to a third of the eventual settlement fund.
An Air New Zealand spokeswoman said the proceedings were filed in 2007.
"Air New Zealand, following thorough internal investigation, found no basis for the claim which it considers to be entirely opportunistic," she said.
"Airfares are highly competitive and very transparent to travellers and travel agents and due to an efficient, international distribution network."
San Francisco law firm Cotchett, Pitre & McCarthy says it does not know how many claimants there will be among hundreds of thousands of passengers who flew during the period. Payments would have to be approved by a United States court and this might not happen until later this year, said lawyer Adam Zapala.
"At this time, it is unknown how much each eligible member of the classes will receive. In order to receive a payment you will need to file a valid claim form. To save time and money, payments will be made at the conclusion of the case," the lawyers say.
Air France, Cathay Pacific, Japan Airlines, Malaysia Airlines, Qantas, Singapore Airlines, Thai Airways and Vietnam Airlines are the "settling defendants" and agreed to pay before the case got to trial, said the firm.
Zapala said they denied liability.
"They have paid out, they say they're not admitting liability but are settling to avoid protracted litigation."
Air New Zealand, All Nippon Airlines, China Airlines, EVA Airlines and Philippines Airlines have not settled.
Zapala said pretrial proceedings including taking of depositions and discovery had taken place but a further appeal was pending before any trial.
This meant the substantive hearing could be two years away, he said.
"We believe we have a good case and we hope to bring some measure of justice to people who feel fares were fixed."
The action is being taken under the umbrella of AirlineSettlement.com and on its website it says one defendant - ANA of Japan - has pleaded guilty to fixing the prices of certain discounted tickets sold in the United States from at least as early as April 1, 2000, until at least April 1, 2004.
Zapala said the case was similar to the global cargo cartel case that resulted in airlines paying hundreds of millions of dollars as a result of action by regulators. Air New Zealand fought that action for several years but agreed to settle two years ago, paying out $7.5 million.
It has since successfully defended a cargo class action filed in Australia and was awarded $3 million in costs. It won another case brought by Australian regulators but that is now under appeal.
