However, the memorandum of understanding signed by chief executives Colin Keel (Queenstown), Richard Roberts (Dunedin) and general manager Nigel Finnerty (Invercargill) will not mean they get involved in sharing Queenstown Airport's ever-increasing passenger load.
In a joint response to Otago Daily Times questions yesterday, the airport CEOs said they had to be ''mindful of our obligations under competition law''.
''Airlines, not the airports, determine where air services are provided, based on their individual commercial and operational considerations.
''For example, a clear demonstration of this process is the recently introduced direct Air NZ service between Invercargill and Auckland.''
The airports are bound by the Commerce Act, which prohibits the lessening of competition by such things as ''cartels'', ''understandings'' and ''arrangements'', or ''taking advantage of market power''.
The Act does enable the Commerce Commission to authorise a restrictive practice, but the airports said applying for authorisation was ''not within the scope'' of the memorandum of understanding.
Finding ways to reduce pressure on Queenstown Airport by ''sharing the load'' with the other two airports has been one of the two main suggestions of Queenstown's Flightpath 2050 group.
Member David Jerram was yesterday cautiously supportive of the memorandum of understanding, but keen to see more detail.
Michael Ross, chairman of the Wanaka Stakeholders Group opposed to the Queenstown Airport Corporation's plans to develop Wanaka Airport for commercial jets, described the announcement as ''great news''.
''There is no down side to collaboration, particularly where there is a real pooling of resources, expertise and capacity.
''The three CEOs should be congratulated for this move, and it is something we've been calling for since our group's inception.
''It's now a question of what the scope and scale of this collaboration is.
''Let's see these airport companies truly work together on bold and innovative strategies to utilise existing airport capacity for the benefit of the whole lower South Island.''
In yesterday's statement, Mr Keel said the airports had been ''discussing opportunities to work together in a number of areas including health and safety, environmental sustainability, operational excellence and supporting strategic regional tourism initiatives''.
Examples included an airport safety week and aviation rescue fire training.
The airports will hold their first ''annual summit'' next month.