The coronavirus epidemic could rob passenger airlines of up to $US113 billion ($170 billion) in revenue this year, an industry body warned on Thursday, more than three times as much as it predicted just two weeks ago as the virus continues to spread around the world.

"In little over two months, the industry's prospects in much of the world have taken a dramatic turn for the worse," said Alexandre de Juniac, president of the trade group, the International Air Transport Association (IATA). The rapid shift in fortune is "almost without precedent," he said.

The effect of the coronavirus is hitting an industry that has already been roiled in the past year by the grounding of Boeing's 737 MAX plane worldwide.

The warning came as British regional carrier Flybe became the first big casualty of the slump in travel demand due to the crisis. Norwegian Air also scrapped its profit forecast for 2020, while US budget carrier Southwest predicted a $US200 million to $US300 million hit to its first-quarter operating revenues.