The airline's chief financial officer, Jeff McDowall, has given notice he will leave after the completion of a planned capital raise mid-next year.
McDowall had been with the national carrier for more than 20 years, and was acting chief executive before the arrival of Greg Foran earlier this year.
"Jeff is playing a critical role in supporting myself and the Board as we rebuild from the ravages of Covid-19, but after a career spanning more than two decades with the airline, he feels it will be time to open a new chapter of his career once the capital raise is complete," Foran said.
McDowall is the sixth senior executive to leave or give notice this year.
Three top executives - Nick Judd, Mike Tod and John Whittaker - were made redundant in a restructuring in May, while its chief people officer, Jodie King moved to Vodafone the month before.
Last month the chief commercial and customer officer, Cam Wallace, left the airline after 19 years service.
The head of research at the investment firm Fat Prophets, Greg Smith, said it was a blow for the company to lose such an experienced person but reflected the changes forced on the airline by the pandemic and the loss of a large part of its international business.
"By its own admission Air New Zealand is going to be a smaller airline for some time and obviously we have seen a lot of costs taken out [of the business] and more to probably go and that's falling on the executive changes as well."
Meanwhile, the carrier has appointed Leanne Geraghty to the newly created position of chief customer and sales officer.
She is currently Air New Zealand's group general manager airports, responsible for for more than 1800 staff and operations across 50 airports internationally.