Thousands jet off on holiday without their luggage as computer glitch brings chaos to Heathrow

Another 6,000 people were locked out of Terminal 3 after a fault in the check-in system led to computer screens which display flight information going blank.

Two flights were cancelled and several more were delayed. A total of 3,000 bags were not loaded onto flights.

Passengers are forced to queue outside Heathrow's Terminal 3 after a computer glitch caused all check-in desks to be shut

Officials closed all check-in desks while they tried to locate the source of the fault and people were told to queue up outside, spilling onto the road.

Several desks were reopened after about an hour and passengers were checked in throughout the evening.

A BAA spokesman confirmed-that there had been 'major disruption'.

'We are working with the airlines this morning to rectify this problem. We sincerely apologise for the inconvenience caused to passengers last night,' he said.

It is the latest embarrassment for BAA, the airport operator, whose reputation has been severely damaged following the disastrous opening of Terminal 5.

More than 250 flights were cancelled on the first day of the airline's move to the £4.3billion terminal on 27 March.

Then an estimated 28,000 items of luggage went missing.

The problem at T3 comes ahead of a Competition Commission (CC) report due next week into BAA's ownership of Heathrow and six other UK airports.

The CC has already published - in April this year - its "emerging thinking" report on BAA which said that BAA's common ownership of seven airports in the UK "may not be serving well the interests of either airlines or passengers".

The commission added that there was concern about BAA's "apparent lack of responsiveness to the differing needs of its airline customers, and hence passengers, and the consequences for the levels, quality, scope, location and timing of investment and levels and quality of service".

There were also worries about "BAA's approach to the system of planning airport development".

In next week's report, the CC could call for a break-up of the "monopoly" enjoyed by Spanish-run BAA which has faced severe criticism from airlines, passengers and politicians.

The commission will also set out its possible remedies which could include the sale of one or more of BAA's seven airports.

Dissatisfaction with BAA's airport performance has been exacerbated by the increased delays which accompanied the stricter baggage regulations introduced two years ago, along with the Terminal 5 fiasco.