A massive battle is taking place in the skies over Europe _ and airplane passengers across the continent are feeling its effects.

A plan to simplify the European Union's patchwork air traffic control system and open up more air traffic duties to private enterprise has sparked strikes and job actions by controllers that began Tuesday in France and were to spread Wednesday to 10 other European nations.

Nearly two decades after the 27-nation EU began eliminating checks along its land borders, its airspace remains a contentious issue.

At the heart of the dispute is the idea of a single European sky _ consolidating the continent's hodgepodge air traffic control systems under a sole authority, turning its many scattered air traffic zones into a few regional blocs, opening up bidding on services like weather forecasting and navigation, and easing what European officials say is a looming capacity crunch.

About 27,000 flights a day now cross European airspace, for a total of over 9 million a year and most are flying under air traffic management systems that were designed in the 1950s, the European Commission said.

Air traffic control workers, however, don't necessarily want to adapt to new proposals put forward by the European Commission on Tuesday. They say they fear threats to passenger safety and to their jobs and claim the EU is yielding to industry pressure to cut costs.

``This is a dispute between European technocrats who know nothing about air traffic control and highly trained specialists,'' said Olivier Joffrin, a French union leader in Paris.

Air traffic controllers in France began a series of strikes on Tuesday, forcing the country's main airports to cut their flight timetables in half just as the busy tourist season was beginning. Some 1,800 flights were cancelled.

``When I came here they told me the flight was canceled. So I had to buy another ticket ... I couldn't wait for a flight next Saturday,'' stranded passenger Ahmed Adouani said at Orly airport in Paris, where he was trying to fly to Algiers.

Air traffic workers elsewhere in Europe were expected to join over the next 24 hours to varying degrees _ from working strictly by the book, to picketing and distributing leaflets, according to the European Transport Workers Federation.

The strikes came the same day that EU Transport Commissioner Siim Kallas called for the speediest possible implementation of the centralization plan, saying the current system's inefficiencies are costing airlines and customers 5 billion euros ($6.6 billion) annually.

``The time has come for more decisive action. If we leave things as they are, we will be confronted with heavy congestion and chaos in our airspace,'' Kallas told the European Parliament in Strasbourg, France, as he introduced the latest plan.

Due to national borders, many flights over Europe take less-than-ideal routes that the EU has estimated add an average of 42 kilometers (26 miles) to each flight.

With jet fuel making up an increasing portion of airlines' costs, and Europe's air traffic expected to increase by 50 percent over the next two decades, the European Commission said acting quickly was crucial.

Some aviation experts blamed Europe's zigzag air routes and overlapping controls for the chaos that followed the April 2010 eruption of a volcano in Iceland. More than 100,000 flights were canceled at the time, affecting an estimated 10 million passengers, as EU countries each imposed different restrictions about how airlines should handle the dangerous volcanic ash floating in the atmosphere.

National air traffic controllers are also often very highly paid, an issue that grates in recession-weary Europe.

Despite Kallas' plea for speed, transport ministers in France and Germany on Tuesday asked for new delays to the EU airspace program that has already been under discussion for nearly 15 years.

Coupled with the strikes, a continued impasse seemed a likely outcome.

French Transport Minister Frederic Cuvillier said France and Berlin were seeking a formal postponement of the airspace plan at the next European summit.

``The plan to create a single European sky is a worthy goal that France initiated, but it has to take into consideration national interests, notably our history of civil aviation,'' Cuvillier told RTL radio. ``This regulatory harassment isn't corresponding to the human side of things, which takes time.''

France in particular is extremely wary of any plans that could cut French jobs.

Kallas countered that even the speeded-up airspace plan would only take full effect in 2020 _ giving plenty of time for workers to adjust.

``What is the problem? It is a very highly skilled group of people who are doing their job in a very sophisticated area of responsibility,'' he said.

Under the European plan, the continent would be divided into nine airspace blocs, instead of the 27 currently in place. The European Commission estimated that, fully implemented, safety would be improved tenfold, airspace capacity would be tripled and air traffic management costs would be reduced by 50 percent.

Francois Ballestero of the Brussels-based European Transport Workers Federation said the European Commission was being unnecessarily confrontational and provoking the controllers' anger.

``We don't want it forced on the countries. Why do they have to force us? This is really a dogmatic approach to liberalization,'' he said.

Ballestero said air traffic control workers in 11 countries would take part in the job action, including Austria, Belgium, Britain, Bulgaria, the Czech Republic France, Hungary, Italy, Latvia, Portugal and Slovakia.

But participation was varying widely. In France, entire control towers walked out while in Italy, for example, union members agreed only to distribute information about their concerns.

There was no job action in Spain, where air traffic controllers became extremely unpopular after a wildcat strike in 2010 and revelations that they were earning an average of 350,000 euros ($463,600) a year with overtime even during the country's severe economic crisis.

Government restrictions on overtime have cut those salaries nearly in half but the air traffic controllers are still reviled by the many Spaniards.

Gesine Meissner, a German member of the European Parliament, said the issue has dragged on for years because it's a power struggle.

``It is not a technological problem. It is a problem of power,'' Meissner said. ``The United States has the same amount of airspace. It is by far more efficient. It is less costly and better for the environment. It is so bad for Europe that we don't succeed.'' (AP)