LONDON (Reuters) - A huge ash cloud from an Icelandic volcano spread out across Europe on Friday causing air travel chaos on a scale not seen since the Sept. 11 attacks and costing airlines hundreds of millions of dollars.

Passengers look at screens showing the flight schedules at Frankfurt airport April 16, 2010. A huge ash cloud from an Icelandic volcano spread out across Europe on Friday causing air travel chaos on a scale not seen since the Sept. 11 attacks and costing airlines hundreds of millions of dollars. REUTERS/Ralph Orlowski

The plume that floated through the upper atmosphere, where it could wreak havoc on jet engines and airframes, threw travel plans into disarray on both sides of the Atlantic.

Severe disruption of European air traffic was expected on Saturday because of the dangers posed by the volcanic ash, aviation officials said. Airports in much of Britain, France and Germany remained closed and flights were set to be grounded in Hungary and parts of Romania.

“I am furious and frustrated,” said Sara Bicoccih, stranded at Frankfurt airport on her way home to Italy from Miami.

The U.S. military had to reroute many flights, including those evacuating the wounded from Afghanistan and Iraq, a Pentagon spokesman said.

For map of ash cloud movement and airline routes, click here

“I would think Europe was probably experiencing its greatest disruption to air travel since 9/11,” a spokesman for the Civil Aviation Authority, Britain’s aviation regulator, said.

“In terms of closure of airspace, this is worse than after 9/11. The disruption is probably larger than anything we’ve probably seen.”

Following the attacks on Washington and New York in 2001, U.S. airspace was closed for three days and European airlines were forced to halt all transatlantic services.

Disruption from the volcanic ash eruption in Iceland is costing airlines more than $200 million a day, air industry group the International Air Transport Association said.

But unless the cloud disrupts flights for weeks, threatening factories’ supply chains, economists do not think it will significantly slow Europe’s shaky recovery from recession or affect second-quarter gross domestic product figures.

“The overall impact should be very limited even if the problem persists for a day or more ... ,” IHS Global Insight chief UK and European economist Howard Archer said.

Vulcanologists say the ash could cause problems to air traffic for up to six months if the eruption continues. The financial impact on airlines could be significant.

The fallout hit airline shares on Friday with Lufthansa, British Airways, Air Berlin, Air France-KLM, Iberia and Ryanair down between 1.4 and 3.0 percent.

Irish airline Ryanair, Europe’s biggest low-cost carrier, said it would cancel flights to and from northern European countries until 1200 GMT on Monday.

David Castelveter, a spokesman with the Air Transport Association of America trade group, said U.S. airlines had cancelled at least 170 flights to and from Europe.

Delta Air Lines, the world’s largest airline, cancelled 75 flights between the United States and European Union on Friday and for Saturday, it has halted 35 flights from the EU to the United States, Delta spokesman Anthony Black said.

PLUME DRIFTING

Joe Sultana, head of network operations at European air control agency Eurocontrol, said the situation was unprecedented. Eurocontrol said it was up to each country when flights were resumed, based on whether there was clear air.

For example, it is clear in parts of Scotland and northern Norway and Sweden, but clear airspace that had been over Vienna and Geneva was closing, so they could be affected.

Mark Seltzer, a forecaster at Britain’s Met Office, said that on Thursday the plume affected northern Scotland because of northwesterly winds at high levels.

“However, the winds have become, at upper levels, more westerly and that is steering it more into Scandinavia, taking it away from Scotland and Northern Ireland.”

The volcano began erupting on Wednesday for the second time in a month from below the Eyjafjallajokull glacier, hurling a plume of ash 6 to 11 km (4 to 7 miles) into the atmosphere.

Officials said it was still spewing magma and although the eruption could abate in the coming days, ash would continue drifting into the skies of Europe.

Iceland’s Foreign Ministry spokeswoman said there was some damage to roads and barriers protecting farms.

“There is still an evacuation of around 20 farms, which is 40 to 50 people,” she added, noting this was less than the 800 people who had been evacuated earlier this week.

MERKEL DIVERTED

Volcanic ash contains tiny particles of glass and pulverised rock that can damage engines and airframes.

In 1982, a British Airways jumbo jet lost power in all its engines when it flew into an ash cloud over Indonesia, gliding towards the ground before it was able to restart its engines.

The incident prompted the aviation industry to rethink the way it prepared for ash clouds.

In addition to travel problems, health officials warned that the volcanic ash could also prove harmful to those with breathing difficulties.

In Brussels, European aviation control officials said some 12,000 to 13,000 flights were likely to operate in European airspace on Friday, compared with about 29,500 normally. The ash was expected to spread further south and east.

German Chancellor Angela Merkel, returning from a trip to the United States, was diverted to Portugal and was expected to spend the night in Lisbon.

However, the Polish president’s funeral looked set to go ahead on Sunday as planned, at his family’s insistence, despite some world leaders being unable to fly in.

The air problems have proved a boon for other transport firms. All 58 Eurostar trains between Britain and Europe were operating full, carrying some 46,500 passengers, and a spokeswoman said they would consider adding more services.

London taxi firm Addison Lee said it had taken requests for journeys to Paris, Milan, Zurich and Salzburg in Austria.

Singer Whitney Houston took a ferry from Britain to Ireland for three concerts in Dublin after her flight was scratched.