The 53-seater X70 coach involved in yesterday's fatal crash was bought by the company in 1995 and underwent a major safety service less than three weeks ago.

Its last routine check was on Friday.

The 175,000 Volvo single-decker - one of 33 in the company's fleet - had double-glazed windows and was fitted with seatbelts throughout.

The X70 runs 230 journeys, seven days a week, between Oxford and Heathrow. Oxford Bus Company marketing manager Jonathan Radley said: "We're very shocked by what's happened. It's a horrendous accident and in the six-and-a-half years I've worked here, this if the first time anything like this has happened.

"We will be co-operating with everyone involved, and obviously our thoughts go out to the families of the driver and passengers."

Mr Radley claimed coach travel was nine times safer than going by car, adding: "Road transport statistics for 1999 show that 1,700 car drivers and passengers died in accidents, but only 11 bus or coach passengers.

"This figure, out of the 3,500 total of all road users killed last year, is very small indeed."