Chirac, who had urged voters to approve the charter in the bitterly contested referendum, announced the result in a brief, televised address. He said the process of ratifying the treaty would continue in other EU countries.

"It is your sovereign decision, and I take note," Chirac said. "Make no mistake, France's decision inevitably creates a difficult context for the defense of our interests in Europe."

With votes counted in all of France and its overseas territories, the "no" camp had 54.87 percent, with only 45.13 percent voting "yes," the Interior Ministry said.

The treaty's rejection in France — the architect of the European project — could set the continent's plans back by years and amounts to a personal humiliation for the veteran French leader.

Although Chirac argued that the constitution would streamline EU decision-making and make the bloc more accessible to its 450 million citizens, opponents feared it would strip France of its sovereignty and generous social system and trigger an influx of cheap labor.

"I think that the constitution will destroy our political structure. It's just about economic interests," said Anne Le Moel, a "no" voter and 42-year-old professor of philosophy, repeating what had become a battle cry among the charter's opponents.

All 25 EU members must ratify the text for it to take effect as planned by Nov. 1, 2006. Nine already have done so: Austria, Hungary, Italy, Germany, Greece, Lithuania, Slovakia, Slovenia and Spain.

Treaty opponents chanting "We won!" gathered at Paris' Place de la Bastille, a symbol of rebellion where angry crowds in 1789 stormed the prison and sparked the French Revolution. Cars blared their horns and "no" campaigners thrust their arms into the air.

"This is a great victory," said Fabrice Savel, 38, from the working-class suburb of Aubervilliers. He was distributing posters that read: "No to a free-market Europe."

EU leaders in Brussels, Belgium, vowed to continue their effort to have the constitution approved.

"I am not a doctor, but the treaty is not dead," said Luxembourg Prime Minister Jean-Claude Juncker, whose country holds the rotating EU presidency. "This ratification process will continue."

The Dutch vote Wednesday, with polls showing opposition to the constitution there running at about 60 percent. On Friday, the constitution's main architect, former French President Valery Giscard d'Estaing, said countries that reject the treaty will be asked to vote again.

France was the first "no" — even though it was a founder member of what over 50 years has grown into the EU.

"There is no more constitution," said Philippe de Villiers, a leading opponent. "It is necessary to reconstruct Europe on other foundations that don't currently exist."

De Villiers called on Chirac to resign — something the French leader had said he would not do — and called for parliament to be dissolved.

Jean-Marie Le Pen, the extreme-right leader who campaigned vigorously for the constitution's defeat, also called for Chirac's resignation.

Chirac "wanted to gamble ... and he has lost," Le Pen said.

The French vote came three days before the charter faces another hostile reception in the Netherlands.

Chirac and European leaders have said there was no fallback plan in the event of a French rejection. But many French voters did not believe that. Many, especially on the left, hoped their "no" vote would force the EU back to the drawing board and improve the 448-clause document. In the meantime, "no" voters expected the EU to continue functioning under existing treaties.

"I voted 'no' because the text is very difficult to understand. Also, I'm afraid for democracy. The way the EU functions is very opaque. Many people there are not directly elected," said Emmanuel Zelez, 32, a film editor.

The outcome caused immediate disarray, with political leaders outside France divided on the significance of the French vote.

British Foreign Secretary Jack Straw said "the result raises profound questions for all of us about the future direction of Europe."

But the European Union's industry commissioner, Guenther Verheugen, said the vote was not a catastrophe and that the situation should not be over dramatized, but he acknowledged that things did not look good for the vote on the charter in the Netherlands on Wednesday.

"It would be a very bitter experience if two founding members of the union, who had always pushed for it, were to vote 'no,'" he said.

Chirac had waged an all-out campaign to persuade nearly 42 million sharply divided voters to approve the charter. But the electorate was in rebellious mood, with unemployment running at 10 percent and wide unease about immigration, Eurocrats and free-market capitalism.

Turnout was close to 70 percent — testifying to the passions that the treaty and the debate surrounding it aroused.

Nicolas Sarkozy, the head of Chirac's ruling Union for a Popular Movement and a leading campaigner for the "yes" camp, called Sunday's defeat "a major political event."

Looking ahead to France's next general elections in 2007, Sarkozy said: "We must decide on an innovative, courageous and ambitious plan of action."

Chirac's popularity ratings have plummeted in recent weeks, and in his television address, the president said he would announce "my decisions concerning the government and its priorities" in coming days.

Nine nations — Austria, Hungary, Italy, Germany, Greece, Lithuania, Slovakia, Slovenia and Spain — already have ratified the constitution.

A "yes," coupled with another by the Dutch, could have given the constitution potentially unstoppable momentum.

In the end, though, the French — torn between wanting to remain one of the engines of an increasingly competitive Europe yet fiercely protective of the generous social welfare benefits they enjoy — stuck with their perceptions that the charter posed another threat to their cherished way of life.

"If you look at every sentence, every turn of phrase, practically every article has a mention of (financial) markets," Anne-Marie Latremoliere, a 57-year-old graphic designer, said after casting a "no" ballot at a polling station near the Bastille.

"We want Europe to be a beautiful place," she said, "and this is certainly not it."