International Air Transport Association (IATA) estimated the airline industry had been hit by $1.7bn (£1.1bn) in total losses due to the Icelandic volcano disruption.
IATA director general and chief executive Giovanni Bisignani estimated that at worst, the six-day flight ban hit 29 per cent of global aviation and affected up to 1.2m passengers a day.
He said that the scale of the crisis eclipsed the events of 11 September, when US airspace was closed for three days.
Bisignani said: “For an industry that lost $9.4bn last year this crisis is devastating. It is hitting hardest where the carriers are in the most difficult financial situation.”
Another report for price comparison website Kelkoo by the Centre for Economics and Business Research, said the nascent recovery within the UK’s travel industry was now in jeopardy as costs associated with the volcano began to escalate.
Kelkoo said the UK travel industry alone has felt a £500m impact on revenue as a result of the chaos generated by a freeze on flights.
Holiday company Tui Travel said it was losing £5m-£6m a day during the crisis, and Thomas Cook said it was losing £7m daily.
As flight restrictions were lifted, members of the travel industry continued to confront the government to explain its slow moving response to the crisis.
TUI Travel boss Peter Long said: “The government’s response to the crisis has been a shambles. It is clear that they underestimated the severity of the consequences of the decision for a blanket closure of the airspace for such a protracted period of time.”
British Airways operated 95 per cent of its scheduled flights from London City Airport yesterday and a full schedule from tomorrow. An additional round trip between London City and Madrid will tomorrow help bring stranded customers home to the UK.