Air New Zealand says it has been in discussions for several months with Virgin Blue about a possible trans-Tasman alliance.
The national carrier made the admission late Wednesday afternoon in response to what it said was media speculation.
It says that no agreement has been reached but that it will advise markets if an agreement is concluded.
The head of research at Forsyth Barr, Rob Mercer, says the talks are most likely about some type of codeshare arrangement.
Shares in Air New Zealand were unchanged at $1.37