Air New Zealand will operate flights between Singapore and Christchurch from December next year following approval for the extension of its joint venture alliance with Singapore Airlines (SIA) to March 2024.

Air NZ will operate a seasonal service between Singapore and Christchurch that will run five times a week from Dec 1 next year to Feb 22, 2020, using new configuration Boeing 787-9 Dreamliner aircraft.

Until now, SIA had been operating the seasonal service three times a week in addition to its daily service between Singapore and Christchurch.

Air NZ chief strategy, networks and alliances officer Nick Judd said the change was introduced to meet growing demand for alliance services, adding that the use of larger Dreamliner aircraft will increase capacity and add more premium seating.

Ms Jenni Martin, Air NZ's head of South and South-east Asia, added: "We have seen strong demand for travel to New Zealand in the South and South-east Asia market recently, and we expect these seasonal services and the increase in frequency during the peak season will appeal to travellers in this region."

In addition to Christchurch services, Air NZ and SIA also offer three daily services between Auckland and Singapore, and a four times a week service between Wellington and Singapore via Australia under their joint alliance.

Tickets for the new Air NZ service will go on sale from Jan 23.