"Unfortunately for us Air New Zealand has a lock on corporates as well as commercial agreements with companies like car rentals," Mr Emeny said.
Whanganui mayor Hamish McDouall said it was a real disappointed the two companies had decided to leave.
"It's a shame that these large businesses are pulling out but it may be an opportunity
for a local car hire service to fill the gap," Mr McDouall said.
A concerned customer rang the Avis head office yesterday after not being able to book a car on Saturday and was told Whanganui was not worth the spend for the franchise.
"In a city of 46,000 people, with Air Chathams flying in three times and out three times, I find that hard to believe, " the customer said.
"I know of two people just last week who picked up a rental in Whanganui to drive to Hastings."
Budget Rent a Car New Zealand was wholly owned by the Avis Budget Group. It is understood that Hertz and Pegasus Rental Cars are the only franchises left in Whanganui.