Virgin Australia will start summer services between Auckland and Newcastle.
The airline will fly three times a week to the New South Wales coastal city between November and February next year.
It will start less than a month after Virgin's final split with Air New Zealand, its partner of the last seven years. From the end of October both airlines will ramp up competition with each other as Virgin launches new flights into Queenstown from Melbourne and between Wellington and Sydney. Air New Zealand is also increasing capacity on the Tasman.
Virgin Australia will use a Boeing 737-800 aircraft and will add 13,000 seats between the two cities on Tuesday, Thursday and Sunday throughout summer.
The airline says it will open up the Hunter Region beyond the city of about 450,000 which is about 160km north of Sydney.
Virgin Australia's general manager of network, revenue and alliances, Russell Shaw, said the new route demonstrated Virgin's commitment to the transtasman market.
''I think it shows we're not going anywhere,'' he said.
"Newcastle is a fantastic destination in its own right, but is also an important gateway to the Hunter Valley wine region, the Central Coast's pristine beaches and a short drive to Sydney. We look forward to opening up this seamless international travel experience for passengers flying from Auckland."
Shaw said the airline would assess the success of the route next year to determine whether to extend the season or increase frequency. It would use aircraft juggled from other parts of its international network but no other services would be reduced.
Flights are on sale for $169 one-way, excluding checked baggage.
Scott Tasker, Auckland Airport's general manager aeronautical commercial, said the launch of the new service was great news for travellers.
"With the two countries being each other's top travel destinations, this service adds yet another convenient direct flight. The service provides more choice for New Zealand travellers wishing to access the Hunter Valley region, and will enable Australian Central Coast residents a new and convenient way to travel to Auckland and the rest of New Zealand," he said.
The new flights will make Virgin Australia the first airline to provide an international service from the upgraded Newcastle Airport terminal.
There have been flights between the two cities. Air New Zealand's budget arm Freedom Air flew the route for a short time in the early 2000s.
Newcastle Airport chief executive Peter Cock said the Virgin services would provide international connectivity the area deserved.
"Community support for direct international services has been extremely strong. New Zealand is our number one unserved market, so it is fitting that the first flight through our new international facilities will be servicing Auckland,'' he said.
About 2.8 million travellers move between Australia and New Zealand each year.