The airline industry organisation IATA expects airlines to lose $US5.6 billion next year - an increase from the $US3.8 billion originally forecast.
It's also reiterated that losses this year are likely to total $US11 billion.
Chief executive Giovanni Bisignani says 2009 has been a horrible one for the sector, but the worst is likely to be over.
He thinks there will be more passengers and increased air cargo volumes next year.
Carriers in the Asia-Pacific are expected to show the biggest improvement, but still posted losses of $US700 million next year, compared to $US3.4 billion this year.
IATA thinks European airlines will lose the most money next year, with an estimated $US2.5 billion between them, while North American airlines are likely to lose a total of $US2 billion.
Latin American airlines are expected to be the only profitable regional group.