Airlines will lose $9bn (£5.7bn) this year, nearly double previous forecasts, as carriers fight to stay afloat in the "most difficult" trading conditions they have ever faced, the industry's leading body has warned.

Buffeted by a collapse in business traffic, falling fares and the threat of resurgent fuel costs, the industry is expected to come close to matching last year's losses of $10.4bn, said the International Air Transport Association (Iata). Revenues are expected to fall by 15% this year, a decline of $80bn, as passenger numbers fall and airlines slash fares to entice a dwindling amount of potential customers. As a result, the forecast industry loss this year has nearly doubled from $4.7bn to $9bn.