The air controllers’ protest action comes as a strike squeezing France's oil refineries spread to new facilities.

The strikes erupted amid a seasonal school holiday in France. Union leaders are hoping to pressure President Nicolas Sarkozy's governing conservatives ahead of regional elections next month.

France's civil aviation agency has ordered airlines to cut back half of the flights in and out of Paris' Orly airport and one in four at Charles de Gaulle amid staffing shortages caused by the walkout.

Five unions of air traffic controllers called the four-day strike to protest conditions of plans to integrate European air traffic control. Workers fear losses of jobs and civil servant benefits.

At an Esso depot, owned by Exxon Mobil Corp., workers went on strike to support their Total colleagues who stopped work since last week over plans to close a plant in northern France.

CGT union organizer Lurent de Launay says the Esso depot in Port Jerome on the English Channel has been closed since before dawn. Esso refinery workers planned to walk out Tuesday afternoon.

Total said more than 100 of the 2,000 Total and Elf gas stations in France had run out of at least one type of gasoline.

Together, Total and Esso refineries account for about 70 percent of France's refining capacity.

President Sarkozy has summoned Total CEO Christophe de Margerie for talks.