The man, who was driving a Toyota Camry, was involved in the accident about five kilometres north of Segenhoe Road around 11.50pm on Sunday.

The passenger, a woman, suffered minor injuries. She was taken to the John Hunter in a stable condition. 

The driver of another vehicle, a Toyota Prado, suffered serious injuries to his legs. He was also taken to the John Hunter Hospital. 

Two dogs were inside the four-wheel drive. One suffered leg injuries and was taken to a veterinarian, while the other was not injured. 

Occupants in the third vehicle, a Mazda hatchback, were not injured.

Crash investigators are examining the circumstances around the incident and are urging anyone with information to come forward. 

The New England Highway was closed in both directions, with local diversions in place since 7am on Monday for light vehicles.

Heavy vehicles were being diverted at Muswellbrook and Scone in each direction on Denman Road, Golden Highway and Scone Road via Merriwa.

This diversion will add around an extra two hours to travel times.

The diversion is not suitable for extended B-Doubles which are being parked.

Due to the nature of the crash there is no forecast of when the highway will reopen.

For the latest traffic information, visit www.livetraffic.com