Continental Airlines, the fifth-largest airline in the US, has said it will lay off 12,000 people and warned it could file for bankruptcy as the impact on US corporations of last week's terrorist attacks on the World Trade Centre and the Pentagon becomes apparent.
Two of the other top five US carriers have slashed flight schedules in the fallout from the attacks. Both Continental and Delta Airlines - which is also expected to cut flights - fly between Ireland and the US.
Several other large US corporations, including the car manufacturer Ford and the manufacturing and financial services giant General Electric, have warned of damage to their businesses.
Ford is to cut car output by 110,000 to 120,000 vehicles and has also warned that earnings in the third quarter of the year will be 10 cents per share below analysts' consensus forecasts.
GE Capital's subsidiary Employers Reinsurance Corp has said it expects to face $400 million after tax claims. GE has warned that its third quarter earnings per share will be 4 cents per share lower than analysts' consensus estimates. Gannett Co, a media group, said the events of last week will hurt September advertising revenues
The airline industry is the most vulnerable sector and the deepening crisis led Mr Gordon Bethune, the chief executive of Houston-based Continental, to predict 100,000 airline job losses worldwide. The situation also prompted the Bush administration to announce it will hold urgent talks with carriers about their financial woes next week.
Aer Lingus, which restarted its transatlantic service this weekend, is working on a restructuring plan to be presented to the company board later this month.
Continental warned that without financial help from the US government, a late-October reorganization of the company under protection from the bankruptcy court would be "prudent".
Northwest Airlines, the number four US carrier, and UAL Corp's United Airlines, the second largest, said they would cut schedules by 20 percent, along with Continental, the fifth-largest airline.
"The US airline industry is in an unprecedented financial crisis," Mr Bethune said.
"Our industry needs immediate congressional action if the nation's air transportation system is to survive."
The lay-offs announced by Continental, which represent 21 percent of its staff of more than 56,000 people, are likely to be followed by job cuts elsewhere. Minneapolis-based Northwest Airlines, which has 53,000 employees, said it would review its overall staffing needs by next week and bring in long-term scheduling cuts by the end of the month.
Among other major US airlines, the world's largest, American Airlines, said it was reviewing staffing. Delta Airlines said it expected the disaster to have a "material adverse impact" on its financial condition. It said it could not rule out lay-offs.
US insurers have warned they face large claims. MetLife Inc said it expects insurance claims of between $250 and $300 million, while PartnerRe Ltd, the re-insurance group, expects insurance claims to be between $350 million to $400 million.