French Prime Minister Dominique de Villepin admitted his disappointment as unemployment rose 0.1% to 9%,or 2.6 million jobseekers, during August.
Failure to check jobless totals puts pressure on Mr de Villepin
The rise is a blow for Mr de Villepin, who has made reducing jobless totals the top priority for his government.
Youth unemployment, running at 21.6% for the under 25s, was the focus of Mr De Villepin's attempts to reform labour laws, which stalled this year.
"It's not brilliant, it's disappointing" Mr de Villepin said.
Analysts had been expecting French unemployment to fall in August after it reached a four-year low of 8.9% in July.
Labour Minister Jean-Louis Borloo questioned the significance of the rise. He pointed out that some seasonal workers had been excluded from the statistics due to technical factors.
French unemployment rose to 2.445 million from 2.436 million in August.based on the ILO (International Labour Organisation) measure.
Meanwhile, the French economy grew at its fastest rate for five and a half years, at 1.2% in the second quarter, according to figures released yesterday. Strong business investment and consumer spending fuelled the increase.
Elsewhere in the Eurozone German unemployment has dipped by 134,000 to 4.2 million.
Mr de Villepin has said he aims to reduce unemployment to below 2 million by 2007.