At the height of the upheaval on Saturday and Sunday, carriers were losing USD 400 million per day, Giovanni Bisignani told reporters in Berlin, calling an earlier estimate of USD 200 million per day "conservative."

The sector has also been left to pick up additional costs like providing accommodation to stranded customers, food and alternative modes of transport to get them home, Bisignani said.

"We've seen a week without revenue but that has not stopped the costs," he said.
He said that in Europe "governments must take their responsibility" and help the carriers, calling the firms victims of "an act of God, completely out of the power of the airlines."
He said however that the situation was different from the aftermath of the attacks on the United States on September 11, 2001, when airlines were bailed out by governments.
After 9/11, "it took a long time to recover because it was an issue of confidence," Bisignani said, saying he hoped that the chaos of the past week was a "parenthesis."

European air travel was slowly returning to normal on Wednesday after volcanic ash drifting from an eruption in Iceland prompted a shutdown last week that left millions of passengers stranded and hit the economy.

The chief executive of Lufthansa, Europe's biggest airline by passenger numbers, said that the firm had no estimate on how much the stoppage had cost the firm but that it was "not marginal."

Britain's Aviation Authority had on early Tuesday extended the flight ban till this morning, but retracted its decision and allowed landings and takeoffs at all airports from last night.
Experts in the UK warned the travel industry faces a "huge logistical operation" as some 150,000 Britons were currently stranded overseas.

The country's Civil Aviation Authority (CAA) announced a "phased reintroduction" of UK airspace from 10pm Tuesday night.

The deal - which amounts to a rewriting of current rules - involves airlines agreeing to making "intensive" ash damage inspections of aircraft before and after each flight. They must also report any ash-related incidents.Plane-makers have agreed to higher tolerance levels for aircraft flying through areas of low ash concentrations.

The decision was made after manufacturers, airlines, the British government and aviation bodies took account of new data and analysis that suggested flights could operate safely in certain circumstances.

CAA chairwoman Dame Deirdre Hutton said "some no-fly zones" would remain, but these would not affect UK airports.A Downing Street spokesman said Prime Minister Gordon Brown welcomed the decision by the CAA to allow the UK airspace to be used.

British Airways will operate all longhaul flights from Heathrow and Gatwick but all shorthaul flights remain cancelled until 1pm this afternoon.No flights have arrived or left Heathrow Wednesday morning.
Other airlines have warned hundreds of flights remain cancelled and urged passengers to contact them before making their way to airports.

The UK no-fly zone was dramatically lifted last night after a game of brinkmanship by British Airways boss Willie Walsh.The BA chief executive sent 26 long-haul flights towards British airports and demanded that the air authorities allow them to land.

At first the planes heading towards Heathrow and Gatwick were turned away but last night Britain's Civil Aviation Authority and air traffic control body NATS caved in and finally ended the flying ban.

Criticising authorities for closure of the airports leading the airlines to lose 200 million pounds a day, Walsh said last evening: "I don't believe it was necessary to impose a blanket ban on all UK airspace last Thursday. My personal belief is that we could have safely continued operating for a period of time." 

Transport Secretary Lord Adonis said all British airports could reopen and he expected them to remain open.

A spokesman for BAA which operates Heathrow, said it would do everything possible to "get people moving".
"We are ready to open, but until further notice passengers must contact their airline before travelling to the airport," the spokesman said.
"Not all flights will operate during the early period of opening, and we will do everything we can to support airlines and get people moving."

The first flights in five days from Europe's largest airport in Heathrow took off soon after the reopening of the air space Tuesday night.Finland kept its air space closed while Norway and Denmark reopened their air space for a short duration last evening. Poland said it would lift the flight ban for all airports shortly.

Meanwhile, volcanologists said the ash plume from the volcano in Iceland decreased as it began spewing more lava, but this could change any time because it still remained active.