PARIS — Former French presidential candidate Segolene Royal is separating from the father of her four children who is also the leader of her Socialist party, the couple announced Sunday.

The announcement came as the Socialists did better than expected in parliamentary elections Sunday, thwarting a landslide victory by President Nicolas Sarkozy's conservatives.

Royal's separation from Francois Holland could complicate their party's efforts to regroup following her May 6 presidential election loss. She is vying to take over the Socialist leadership.

The couple met three decades ago as students at France's school for the political elite and had four children but never married. Their relationship had shown increasing signs of strain, including public policy disagreements during her presidential campaign.

News of their separation distracted from the Socialists' better than expected election performance. Although Sarkozy's UMP and its allies won a comfortable majority, the president's party won fewer seats than it used to have.

Royal told The Associated Press that she was "furious'' that word of the separation leaked on election night. She said the couple had wanted to make a statement later in the week. Hollande later confirmed that they were separating in his own statement late Sunday.

In a country where the standard greeting is kisses on the cheek, Hollande and Royal were photographed shaking hands in March, a snapshot that raised eyebrows. Hollande also had said before Royal's election defeat that he would not, if she won, live with her in the presidential palace.

Royal and Hollande are suing the authors and publisher of a book, "La Femme fatale,'' which describes strains in their relationship. In a separate book of interviews in March, Royal had dismissed rumours that she and Hollande no longer lived together.