PARIS, Oct. 18 — For President Nicolas Sarkozy, a day does not get much darker than this.
On Thursday, Mr. Sarkozy, the 52-year-old French leader, was reeling from blows on two different domestic fronts: a wave of strikes that swept through France and an official announcement that his 11-year marriage had come to an end.
Shortly after a presidential spokesman, David Martinon, told a hastily called news conference that he had absolutely no comment about his boss’s marriage, the Élysée Palace dropped the bombshell that Mr. Sarkozy and his wife, Cécilia, “announce their separation by mutual consent.” The palace later clarified that the couple “had divorced.”
Other French leaders have led unconventional love lives. One president, Félix Faure, died in the bed of his mistress in 1899; another, François Mitterrand, fathered a daughter with his mistress.
But Mr. Sarkozy, who was previously married and divorced long before he was elected president, is the first to divorce while in office.
Immediately after the news was broadcast on radio and television, striking protesters in the port city of Le Havre shouted: “Cécilia, we are like you! We are fed up with Nicolas!”
The Élysée Palace statement, which ended weeks of speculation, said that neither the president nor Mrs. Sarkozy would comment on the news.
The announcement coincided with a national strike in the public sector — the first in Mr. Sarkozy’s five-month presidency — to protest the conservative government’s plan to eliminate special retirement privileges that employees in private businesses do not enjoy. Labeled “Black Thursday” by the news media, the 24-hour strike halted most trains, subways and buses throughout France and canceled classes in many schools and universities.
State unemployment offices and many museums were closed. Mail delivery was uneven. Some Paris theatrical performances were called off.
Workers at the state-owned electricity and gas utility giants joined the walkout, leading to a reduction of 16 percent in electricity output by the country’s nuclear reactors. The ultimate indignity for Mr. Sarkozy was that power was cut off to La Lanterne, which he is using as a secondary residence, in Versailles.
Some unions threatened to continue their protests beyond Thursday, but the news gripping France was not the strike — the French are used to those — but the announcement that the Sarkozys had ended their marriage.
Mrs. Sarkozy has been out of the public eye recently, but last week, she posed — at her request — on the balcony of a Paris hotel for the cover of Paris Match, whose latest edition appeared on the newsstands on Thursday.
She was said by the popular weekly magazine to have been unhappy with unflattering pictures of her that had appeared recently in the news media. She chose the same photographer who had taken her husband’s official presidential portrait.
The three-page Paris Match spread showed her staring vacantly into the camera next to the caption “Cécilia Sarkozy, a Serene Woman,” but it revealed nothing about the state of the Sarkozy marriage. Her whereabouts on Thursday were unknown, although friends said she was preparing for an engagement party this weekend for her 20-year-old daughter, Jeanne-Marie, one of her two children from a previous marriage. Mr. Sarkozy also has two adult children from his first marriage, and the Sarkozys have a 10-year-old son, Louis.
Asked in a telephone interview about Mrs. Sarkozy’s plans, Carina Alfonso-Martin, her spokeswoman, said: “I don’t know them. This is her private life. It’s up to her to say.”
Mr. Sarkozy kept to his daily schedule and traveled to Lisbon on Thursday afternoon for a two-day meeting of the leaders of the European Union. He will be accompanied on a state visit to Morocco next week by Rachida Dati, his minister of justice.
The opposition Socialist Party suggested that Mr. Sarkozy timed the announcement of the divorce to coincide with the strike, perhaps in an attempt to mute its news impact.
“The Élysée has chosen this Thursday, a day of strong social mobilization, to make the information official,” said Annick Lepetit, the Socialist Party’s national secretary, in a communiqué. “We will leave it to the French people to judge if it’s only a simple coincidence.”