Delegates gather at the Trenz conference at the Rotorua Energy Events Centre. Photo: NZME

Sydney or Melbourne flights to and from Dunedin appear no closer to reality, but Air New Zealand says it will continue to consider the possibility.

Chief revenue officer Cam Wallace told the Otago Daily Times at the Trenz tourism conference in Rotorua yesterday such flights were ''not on the table''.

Flights have run in the past, but despite regular calls from Dunedin to reinstate them, the only international flight from Dunedin is a Brisbane service.

It was a market Air New Zealand assessed ''relatively regularly'', to find out what the demand was, Mr Wallace said.

In its evaluation of the suitability of the market, the company took the capital cost of an aeroplane, considered how it could be scheduled between two airports, and did a ''quite extensive analysis'' of what market demand existed.

There were well-established models of how many more people might travel if a route was introduced.

The types of travellers were also considered, whether they were travelling for leisure, to visit friends and relatives, or for business.

A mix of all three was important, as there was a difference to how much the different groups were prepared to pay.

Operating costs were also added to the mix.

''When you deploy an aircraft you're putting a $55million or $100million asset in a market.''

The company also needed to consider where else it might be used.

''It's probably one of the biggest decisions we make.

''We have tried before, and it hasn't met our expectations.''

Mr Wallace said the airline did not completely dismiss the idea as a possibility for the future.

''It's one of those markets we think all conditions going well, circumstances can change.

However, ''from our perspective at the moment there's no concrete plans''.

The company spent lot of time talking to Dunedin Airport chief executive Richard Roberts, a ''major and compelling advocate'' for the idea.

''The voices from Dunedin are well heard at Air New Zealand head office.''

Domestically, Air New Zealand was happy with seat numbers to and from Dunedin, and had no plans to change them.