The International Air Transport Association predicts the global aviation industry could lose $US9 billion this year - nearly double an estimate issued three months ago.
More than 500 aviation industry leaders are in the Malaysian capital Kuala Lumpur for the association's annual meeting.
Industry executives say the prospects of a recovery look slim this year, despite signs the global economy is stabilising.
Air New Zealand chief executive Rob Fyfe expects demand for air travel to get worse before it gets better.
Orient Aviation magazine chief correspondent Tom Ballantyne describes the mood at the meeting as dismal.
While there's a feeling things could start improving later this year, or early next year, he says there is still a lot of uncertainty.