The airline is losing $5m a day

Last week, the unions finally accepted pay cuts in order to save American Airlines from bankruptcy.

But, shortly after the vote had gone through, it emerged that senior management were to receive bonuses and a special pension fund.

That has caused the unions to threaten to backtrack on their original vote in favour of the austerity measures.

The renewed likelihood of bankruptcy caused the share price of the airline's parent firm, AMR, to drop by 23% during Monday trade.

Legal trouble

American Airlines has already dropped plans to award the controversial bonuses to its top executives.

But outraged union leaders are meeting managers on Monday, threatening to rescind the vote.

Jim Little, the director of the union representing mechanics and ground workers, said unions had only been informed of the perks through a filing with the Securities and Exchange Commission, as the rank and file were concluding a vote on the concessions.

"If members had known about these compensation agreements, there would have been a higher turnout of No votes," he said.

The legality of rescinding the vote is also in question.

Massive losses

The latest row gives the long-running battle between pilots, flight attendants and managers a final twist.

Flight attendants initially rejected their share of the cost-cutting plan, but reversed their decision on Wednesday, after the company extended the original deadline.

Under the plan, American Airlines' managers are to continue to run the business and cut losses, rather than handing the firm over to a judge who would have taken control if the company had filed for bankruptcy protection.

The airline says it is losing $5m (�3.2m; 4.6m euros) a day.

Over the past two years, it has made losses of $5.3bn as a result of a weak economy, the effects of the 11 September attacks and tough competition from low-cost operators.