Air New Zealand has been accused of doing too little to market its flights from Dunedin to Australia.
The airline has announced it will suspend its flights from the city to Sydney from April.
At present, the airline operates two trans-Tasman services a week between Dunedin and Sydney, and two services a week between Dunedin and Brisbane.
But it said over the past three months, almost all planes on the Sydney route have been just half full. The service would be suspended during the off-peak winter months between April and October.
The Dunedin to Brisbane route is to be reduced to one flight a week during May and June.
The changes come into effect in April.
Dunedin Airport chief executive John McCall said Air New Zealand has done too little to market its trans-Tasman flights from the city.
He compares it to marketing by Jetstar, which does not fly from Dunedin, but advertises in local media and has its logo painted on local buses to promote its flights out of Christchurch.
Mr McCall said Jetstar has managed to capture a significant part of the local market by this promotion.
Last week, Air New Zealand announced it would stop its last trans-Tasman service from Hamilton to Brisbane in April because the service was no longer viable.
In October, it announced an end to its flights from Hamilton to the Gold Coast and Sydney.
Air New Zealand said loadings out of Hamilton to Brisbane have averaged 58% over the past three months, which is clearly unsustainable in the current economic climate.
Meanwhile, two Hamilton City Councillors are urging residents to boycott Air New Zealand international flights.
Councillor Gordon Chesterman said he hoped travellers from the region would start booking international flights out of Auckland using other airlines. He believed that would send a strong message to Air New Zealand.
However, airline analyst Peter Clark said the days of carriers flying international services from provincial cities are over.