Singapore Airlines is seen as a possible buyer of Air New Zealand's 25.9 per cent stake in Virgin Australia if it opts to sell out.
Air New Zealand is considering a sale of the shareholding, spurred by its reluctance to keep chipping in to support the highly geared Australian carrier and a feeling that Air NZ's investment is out of proportion to its size.
Analysts at Morningstar say the combined equity and debt investment of $563 million compares to Air New Zealand's total asset base of $7.2 billion and equity of $2 billion.
Air New Zealand bought into Virgin as a way of securing its joint venture on the transtasman route at a time of a possible threat from Singapore Airlines' Australasian ambitions.
Singapore and Etihad later also bought in to Virgin.