Smash hit

"Just as the Government is about to make the decisions that could lead to the first full-length runways being built in the South East since the second world war, the commission risks creating uncertainty, delay and confusion at exactly the wrong time," he added.

BAA, which conceded that there was a need "for improved service from the airport operator", went on to say that it would continue to challenge the commission's findings through the remaining months of the review. The commission's final report is set to be published next April, but is likely to reflect the substance of its provisional findings.

On its other airports, BAA said: "In Scotland, the commission has apparently ignored the evidence presented by BAA, and supported by numerous respected third-party organisations, that clearly demonstrates that Edinburgh and Glasgow airports serve separate markets and therefore do not and would not compete, regardless of ownership.”

Airlines applauded the regulator's findings but called for the system of economic regulation to be reviewed.

In pictures: New London airport opened

Heathrow Airport has been handed over to the Ministry of Civil Aviation

Letter: The Gatwick project, 1952

Some of us do not share Lord Douglas's enthusiasm for building the 'Clapham Junction of the air' in England's green and pleasant land

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British Airways, the biggest airline at Heathrow, said: "The focus must be on ensuring that the current regulation of BAA's London airports is strengthened. The right conditions must be put in place to provide good service quality standards, cost efficiencies and infrastructure improvements that customers demand."

A spokesman for the full-service airline added: "We would support the introduction of a licence system, as in other regulated industries."

Andy Harrison, chief executive of easyJet, which operates from Stansted, Gatwick, Edinburgh and Glasgow, said simply selling one of BAA’s airports would not deliver a better deal for passengers.

“It’s a good start and we are very pleased that the Competition Commission has recognised what is a fundamental problem for UK airports. But the solution is better regulation, because each one of these airports — including those in Scotland — are local monopolies and they need better regulation, not simply being sold to another highly-indebted owner," Mr Harrison said.

Ryanair, a fierce critic of BAA, which has a base at its Stansted airport, welcomed the Competition Commission's findings. "BAA’s monopoly control over the London airports has been highly detrimental to competition and consumers. BAA has long ignored the needs of its airline users and the travelling public and provided inefficient, gold plated facilities, encouraged by an ineffectual regulator, the CAA," a spokesman said.

BAA was formed in 1965 and was the subject of a fierce takeover battle in 2006, which was won by Ferrovial, the Spanish property group. The airport operator has come under fire from politicians and airline bosses for long queues and poor service at Heathrow and Gatwick in the past two years, culminating in the bungled opening of Heathrow's Terminal 5 in March.

Most recently, thousands of customers were left without their bags at Terminal 3, after a "computer glitch" meant that 3,000 flyers were forced to wait hours for their luggage.

Nigel Rudd, chairman of BAA, told the BBC at the weekend he expected the review to recommend disposals and that it would not be a disaster of the company had to sell some assets.

The sales will help Ferrovial pay down some of the £8.97 billion worth of debt it racked up to buy BAA in 2006 as part of its push to diversify from construction.

Shares in Ferrovial, which is listed on the Madrid stock exchange, rose 1.38 per cent to €33.82 in early trading.

Total debt at the end of last year stood at €30 billion, while Ferrovial shares have fallen 45 per cent in the past 12 months and have underperformed European construction shares by 16 per cent. Worries over refinancing the debt, potential hitches at BAA and Spain's economic slowdown have weighed on the stock.

The UK airport sales would attract significant interest. Germany's Fraport and construction group Hochtief have both declared an interest, and London City Airport co-owner Global Infrastructure Partners, Australia's Macquarie and Manchester Airports Group are also expected to play a part. Balfour Beatty, which owns Exeter and Blackpool airports, has said it could be interested in buying one of BAA's smaller airports.

Macquarie has a global team of executives who look at markets around the world for potential opportunities just like this.

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