Saturday classes in primary schools will be scrapped from next year and secondary schools could follow suit, the French government has said.
Scrapping Saturday school is popular with teachers and parents
Education Minister Xavier Darcos said the three hours thus freed would be used to teach underperforming students.
French students spend 936 hours per year in class, compared to an average of 800 in the rest of Europe.
Parents and teachers favour shortening summer holidays to make up for the lost Saturdays, opinion polls show.
"As soon as the next school year, work on Saturdays will stop everywhere in France's primary schools and I hope we will be able to extend the move quickly to secondary schools," Mr Darcos told TF1 television.
Freed time, he added, would be used to cater "for those that most need it", a category comprising 15% of students, according to a recent study by the High Council for Education.
Two-thirds of primary children attend school on at least one in three Saturdays.
Mr Sarkozy has an 11-year-old son who attends classes on Saturday
In Paris, they alternate Saturdays and attend classes on Wednesday mornings, while most children have that day off.
The interrupted schedule dates back to when Thursdays were devoted to Catholic instruction and children attended school all day on Saturday.
Eighty per cent of parents and 59% of teachers are opposed to Saturday classes.
President Nicolas Sarkozy, himself the father of a 11-year-old, agrees with parents, saying weekends are disrupted and too short.