Heathrow's managing director, who oversaw the calamitous opening of Terminal 5, resigned yesterday in the latest high-profile departure from BAA, the airports operator.

The company said that Mark Bullock had “chosen to leave” after recent management changes by Colin Matthews, the chief executive.

Mr Matthews is merging the corporate operations of BAA with Heathrow to focus more on the running of Britain's biggest airport.

Although Mr Bullock was given a place on BAA's board, it is understood that he was unhappy with his position in the merged operation.

Mr Bullock, who has worked for BAA for four years, will be replaced by Mike Brown, chief operating officer of London Underground. BAA said that Mr Brown had experience of both operations and customer service.

Mr Bullock was in charge when hundreds of flights were cancelled and tens of thousands of travellers lost their luggage after the £4.3billion Terminal 5 opened.

Mr Matthews said: “Mark Bullock has made a significant contribution to BAA and to Heathrow in particular and has led the airport through a particularly challenging period. I am grateful for his efforts.

“I now look forward to working with Mike Brown as we continue driving passenger service standards across the airport and focus on the important work to transform the facilities we provide for passengers and airlines.”

Mr Bullock said: “Leading the team at Heathrow is an intense and demanding role but one I have enjoyed very much. The managing director role at the airport will change substantially under the new structure being introduced by Colin Matthews and, while I understand and support those important changes and the renewed focus on day-to-day operations, the time is clearly right for me to move on and take on new challenges.”

Mr Bullock's departure follows a series of executive departures at BAA, which operates seven airports in the United Kingdom, including Heathrow and Gatwick.

Ferrovial, BAA's Spanish owner, yesterday revealed that operating costs had climbed 33 per cent at the airports group as it footed the bill for the opening of Terminal 5 and for extra security and maintenance.

The infrastructure group, which bought BAA two years ago, said that it was more optimistic about refinancing its £10billion BAA debt.

Ferrovial has already had to ask its shareholders for a £400million cash injection.

Nicolas Villen, the finance officer, said: “We feel more optimistic than a few weeks ago about the completion of the refinancing. We are making good progress on the bank facility, good progress on the ratings and good progress on the documentation.”

BAA is trying to establish the identity of its bondholders to negotiate with them, too.

It has been suggested that BAA will have to sell Gatwick to help with its refinancing.

The Competition Commission has also raised strong concerns over the lack of competition between airports in the South East of England.

Macquarie, the Australian investment bank, has been advising BAA for the past few months on the possible sale of some assets.

Ferrovial reported a fall in profits for the first quarter from €450million (£358million) last year to €78.5million. The 83 per cent fall was in line with analysts' expectations and Ferrovial said that the drop partly reflected the impact of the sale of BAA's World Duty Free unit and stakes in Australian airports.

Airport carousel

The departure lounge for executives checking out of BAA and BA is becoming crowded.

Yesterday Mark Bullock, the managing director of Heathrow, became the latest to fall on his sword. Mr Bullock is one of three executives who were at the centre of the opening of Terminal 5 to leave their jobs. Last month British Airways announced that Gareth Kirkwood, its operations director, and David Noyes, customer services director, were to go.

At BAA, the airports operator, a series of executives have quit over the past year. The most notable was Stephen Nelson, the chief executive, who went in February.

He was replaced by Colin Matthews, former chief executive of Severn Trent, the water group, who was seen as having more experience of operations. Mr Nelson was ousted by Sir Nigel Rudd, who took over as chairman last September. Mr Nelson had known that the writing had been on the wall for his departure since before last Christmas, Sir Nigel said.

Last year Tony Douglas, then head of Heathrow, resigned, as did Greg Ward, the operations director, who was in charge of security checks. Mr Douglas left BAA shortly after saying that Heathrow was “bursting at the seams”.

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