United last year filed aviation's biggest ever bankruptcy

And the company - whose losses amount to $13m a day - warned that its financial position was likely to deteriorate because of the war in Iraq.

United is not unusual among US full-service carriers in finding business tough but its problems have appeared the severest.

Last December, it filed the largest bankruptcy in aviation history.

Workers face pay cuts

United chief financial officer Jake Brace said the war presented "serious challenges" and would have a negative impact on the airline although it was moving rapidly to address them.

The company has already cut capacity by 8% in April and is sending some workers on unpaid leave. It is also actively seeking financial help from the US Government for the industry as a whole.

"Given the uncertain situation, further temporary reductions in employee compensation may be needed in the future," United added on Wednesday.

"The pressure is mounting for the company to quickly come to terms with labour and get some of the additional cost cuts in place to stem cash losses," said William Warlick, an analyst at Fitch Ratings.

"March will be weaker as a result of the fall-off in demand that became apparent by mid-month [because of the Iraq war]. April is likely to be weaker than March."

The company's shares moved two cents higher to 87 cents.