BERLIN — Air controllers lifted all restrictions on German airspace today, paving the way for more flights into one of Europe's busiest airports. Airlines announced they had lost at least $1.7 billion and criticized government actions during the volcanic ash crisis.

Giovanni Bisignani, the head of the International Air Transport Association, called the economic fallout from the six-day travel shutdown "devastating" and urged European governments to examine ways to compensate airlines for lost revenues, as the U.S. government did following the Sept. 11, 2001 terror attacks.

Spain, meanwhile, has become a key emergency travel hub, arranging for hundreds of special flights to move over 40,000 people stranded by the travel disruptions. Its airports and airspace have mostly remained open throughout the crisis.

German aviation agency Deutsche Flugsicherung said the improved weather situation allowed it to completely reopen the country's airspace, ending restrictions that had hobbled air travel and contributed to millions of travelers left stranded around the globe.

"Bremen, Hamburg, Hannover, Berlin, Frankfurt and Munich are open again," said Axel Raab, a spokesman for German air traffic control, adding that airspace was expected to remain open for the rest of the day.

"We cannot say what it will look like in the next few days. If the volcano becomes active again, new closures might happen," he said. "This is now a decision that was made based on meteorological data."

The agency added that the concentration of volcano ash in the sky "considerably decreased and will continue to dwindle because of the weather conditions." Passengers, many of whom were stranded for days, welcomed the news.

"It's good for us at least," Mats Tillander, a Swede at Frankfurt International Airport, who spent four days trapped in Texas, told AP Television News.

He discounted bickering between airlines and governments as to whether the airspace closings across Europe were a case of overkill.

"I don't know what's right and wrong," he said. "If they should have done it earlier, I don't know."

Airlines lost $400 million each day during the first three days of grounding, Bisignani told a news conference today in Berlin. At one stage, 29 percent of global aviation and 1.2 million passengers a day were affected by the airspace closure ordered by European governments.

Flights resumed in many areas, but the situation was anything but normal as airlines worked through an enormous backlog after canceling over 95,000 flights in the last week.

Severe delays are still expected across Europe, as airlines pressed to patch together normal flights with airplanes and crews scattered all over the globe.