FirstGroup said in a statement that it was sorry for failing to provide expected levels of service on First Great Western (FGW) and First Capital Connect (FCC), which run services in western England and on commuter routes north and south of the Thames respectively.

Overall satisfaction with FGW and FCC fell six pct and five pct to 72 pct and 71 pct respectively, according to the National Passenger Survey by Passenger Focus.

First has faced heavy criticism for the performance of the two franchises since it took them over last year.

Passengers in the south west protested against sweeping service cuts and reductions in rolling stock that First imposed after taking over services formerly run by National Express' Wessex franchise. The outcry forced FGW to review the service reductions and to introduce more carriages.

FCC provoked a storm of protest when it stopped passengers using cheap day returns on services out of London in the evening peak.

First said in its statement that the survey was undertaken in January and February, at a time when many passengers were experiencing delays due to infrastructure failures outside its control.

'Since that period, operations and services have improved considerably,' it said.

Managing director of the group's trains division, Andrew Haines, said the company is aware of the overcrowding problems on its services and is planning to increase capacity.

'The first thing we offer is an unreserved apology,' Haines told London's Evening Standard.

Overall passenger satisfaction with the UK railways has fallen for the first time in three years, by two percentage points to 79 pct, the survey showed.

Only 40 pct of passengers think they are getting good value for money and 26 pct are unhappy with the amount of room they have to sit or stand.

As well as those expressing dissatisfaction with FCC and FGW, passengers using another FirstGroup franchise, First Scotrail, and those travelling on Northern Rail, run by Serco Group PLC, said a number of their services had got worse.

However, the watchdog said 87 pct of passengers travelling on long-distance trains were satisfied with their journey overall.

National Express Group PLC franchise Midland Mainline climbed to the top of the satisfaction ratings in the long distance sector, satisfaction with train facilities at First Transpennine Express had improved by 25 pct due to new rolling stock and Arriva Trains Wales, John Laing's Chiltern Railways and National Express unit Central Trains had also improved in a number of areas.

National Express welcomed the findings of the survey, noting that its Gatwick Express franchise, which it is shortly to lose to Go-Ahead's Southern franchise, came top in 21 out of 32 performance measures for regional train operators.

The chief executive of National Express' trains division, David Franks, said: 'These results clearly demonstrate our passion and drive to improve the service we give our passengers.

'This applies not only to train performance, where we lead the industry, but also to the investment we have made in the training and development of our people.'

The survey was conducted at more than 650 stations between Jan 22 and Mar 25, 2007.