BRUSSELS (AFP) - EU transport ministers presses for accelerated moves toward creating a single European sky for air traffic control as a new cloud of volcanic ash threatened more travel chaos.

• Air traffic chaos: day-by-day timeline
• Scotland and N.Ireland airspace closed
• British and Irish airspace closed after new ash risk

A six-hour shutdown of Irish airspace, because of fallout from the Eyjafjoell volcano in Iceland, was a fresh reminder to European governments of the potential disruption, with ash still spewing out and the summer holiday season looming.

Ireland's Transport Minister Noel Dempsey was one victim of the airspace lockdown, unable to get to the ministerial meeting in Brussels where his 26 European counterparts set up a crisis cell to coordinate future action when flights are threatened.

They also agreed that Europe must speed up moves started in 1999 to set up a pan-European air traffic control system to replace the current patchwork of 27 separate air spaces.

Ireland is in the forefront of that project. In 2008 it created, with Britain, the first "functional airspace bloc" to coordinate air traffic.

France, Germany, Belgium, Luxembourg and the Netherlands plan to form another such bloc and French Transport Secretary Dominique Bussereau said his country would sign the treaty creating the bloc by the end of the year.

The 30 billion euro (40 billion dollar) cost of the technology required for the SESAR Single European Sky is putting off some airlines who will have to fork out most of the funds.

After the Iceland volcano erupted on April 14, European nations took individual decisions to ban flights because of the threat to jet engines, with very little consultation with other governments.

"On April 15 and 16 it was chaos," said EU Transport Commissioner Siim Kallas, who highlighted how 100,000 flights were cancelled and more than 10 million passengers stuck around the world.

Authorities have now divided the sky into three zones, according to the risk level -- red where the ash is too dense for jets to fly, grey where the risk is considered acceptable and an open zone.

The ministers did not hold talks on the finances for the technology, nor any compensation for the airlines. The airline sector says it lost about 2.5 billion dollars in the volcano shutdown although Kallas highlighted this was a preliminary figure.

The European Commission and consumer groups increased pressure on airlines to reimburse passengers hit by the ash chaos.

"Today thousands of consumers affected by flight disruptions are still rightly clamouring for their rights to be respected in practice," said EU Health and Consumer Policy Commissioner John Dalli.

"My message to them is: do not hesitate to claim what is yours. If an airline or a tour operator continues to ignore your rights, a European Consumer Centre near you can be your next port of call," he added.

The commission, the EU's executive arm, also favours scrapping certain night flight restrictions in such cases to allow the swifter repatriation of stranded passengers, who numbered in their hundreds of thousands worldwide last month when the ash cloud shut down airspace in much of Europe.