Heathrow bosses spend less but earn more from shops

They will deepen concern among airlines that Grupo Ferrovial, which paid £10.3billion for BAA last summer, is trying to boost its profits from its investment at the expense of long suffering passengers.

The accounts come ahead of an important report from the Competition Commission, which is expected to say that an end to BAA's stranglehold on London's three major airports is one of the options for the future of aviation in the south-east.

In the year since it bought BAA, the Spanish construction company has invested £ 252million in Heathrow, 15 per cent below the £298 million it spent in its last year as an independent company. This does not include the £800 million invested this year on Terminal 5.

Meanwhile revenue from Heathrow has grown from £1.077 billion to £1.232 billion, according to the accounts from FGP Topco, the vehicle used to acquire BAA.

It is not clear how much profit it has made from Heathrow but, as the Evening Standard revealed last week, the final set of figures from BAA suggest they would hit a record £ 600million in 2007.

Most commentators believe that Ferrovial would sell Gatwick if forced to dispose of one of its airports because Heathrow is so much more profitable although leading aviation figures said Ferrovial had not appreciated Heathrow's importance to the British economy when it bought BAA.

Sir Michael Bishop, chairman of bmi, said: "Ferrovial has come into this infrastructure asset thinking they are immune to competition but their customers are not. BAA and Ferrovial have to be encouraged to do more."

A spokesman for Virgin Atlantic said: "It is now more essential than ever that the Competition-Commission look at the current system of airport ownership and ask themselves how it can be done better - because it can be done so much better."

The decline in Heathrow's investment coincides with the airport - the world's busiest international hub - coming under fire over the poor state of terminals and long queues at check-in and security. The Mayor, Ken Livingstone, said last week that Heathrow shamed the capital, and Kitty Ussher, Economic Secretary to the Treasury, has claimed Heathrow is discouraging business executives from travelling to the UK.

This steady flow of criticism is starting to affect Ferrovial's share price, which fell sharply on the Madrid stock exchange yesterday.

A spokesman for BAA said: "It is not the case that we are taking money out of Heathrow. The capital expenditure figures don't take account, for example, of the extra £20million we have put into security to reduce queues."