"Air ambulance services are more than a transport service. They play a critical role in how we respond to health emergencies," says manager community and ambulance Andy Inder.
"A good air ambulance service has four key elements: optimal time, appropriate clinical crew, the right equipment and the right destination. With these working together well, patient outcomes can be improved.
"That's why we are taking the time to work with the preferred tenderers, as well as district health boards, to ensure patients needing urgent clinical support get the right clinical care at the right time."
The agreed providers for each region will be announced as the negotiations are concluded. The first announcement is expected later in September.
NASO, the National Ambulance Sector Office, is managed jointly by the Ministry of Health and the Accident Compensation Corporation (ACC).
Both the Taupo and Rotorua rescue helicopter bases were left off NASO's original request for proposals for air ambulances, prompting local protests. In the Central Plateau area widespread concern has been expressed about the impact on people needing urgent search and rescue help if there is no local helicopter available.