Airline losses, second quarter

United: $292m American: $105m US Airways: $24m

The biggest loser was United, which dropped into a $292m loss, compared with a $374m profit in the same quarter of 2000.

The company said it expected to remain in the red for the rest of the year.

American Airlines, the world's biggest carrier, lost $105m - compared with a $285m profit in the second quarter of last year - and also predicted no end to the current gloom.

Premium plummets

Lying behind the current airline slump is a sharp decline in business travel, once a lucrative premium-rate market for all airlines.

Companies have reined in their travel budgets this year, in response to fears of a US recession.

This has hammered margins: US Airways, which lost $24m in the second quarter, said revenues per seat mile were down 11%.

All three airlines said they were looking at ways to trim costs and excess capacity.

These measures include retiring old aircraft, freezing hiring, and cutting out unprofitable routes.

The news may be a further blow to United's ambitions to merge with US Airways, a deal that has been mired in legal wrangling.

It could also have a knock-on effect on aircraft manufacturers.

Earlier on Wednesday, Boeing announced a relatively buoyant set of second-quarter figures, showing profits growing by a healthy 23% year on year.