Air New Zealand's (ASX:AIZ, NZE:AIR) group capacity fell 1% year on year in December 2025, according to a Friday filing with the Australian and New Zealand bourses.

Long-haul available seat kilometers (ASKs) plunged 5.9%, and domestic ASKs climbed 1.3%, the filing said. Short-haul international ASKs rose 6.8% year on year, helped by the arrival of two new A321 aircraft.

Group year-to-date underlying revenue per available seat kilometer surged 2.2% from the prior year.

The airline carried 1.6 million passengers in December, unchanged from the year-earlier period, per the filing.

The passenger load factor rose to about 85%, from around 84% a year earlier.

The company's Australian shares fell almost 1% in recent Friday trade.