Transport group Stagecoach, which runs one of Oxford's two bus companies, has tumbled into the red.
This reflects a dramatic downturn in its Coach USA arm, which is still suffering from the slide in the US economy.
Stagecoach ran up pre-tax losses of £524.1m in the six months to October 31, against profits of £35.5m last year.
But the firm said it was enjoying good revenue growth in its UK bus operations. Stagecoach chief executive Brian Souter said the group would be closing or selling a host of its North American operations as it reshapes the business.
Perth-based Stagecoach wants to concentrate on scheduled and commuter bus services in the USA and get out of the volatile tour and charter markets.
The group warned two months ago that its Coach USA business was
It bought Coach USA in 1999 for £1.2bn but is now writing-down the value of the division by a hefty £575m.
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