The new team, in its first day on the job, was to hold its first cabinet meeting later on Friday, government spokesman Jean-Francois Cope said.
The opposition criticised the new team as being too similar to the exiting government. Socialist Party spokesman Julien Dray predicted that it "won't last two years".
President Jacques Chirac's mandate ends in 22 months.
"This government can't provide the needed impetus," centrist lawmaker Maurice Leroy said in an interview in the daily Le Parisien.
New Prime Minister Dominique de Villepin has promised to tackle double-digit unemployment and return confidence to the French by giving "new impetus" to the government.
There will be a "very strong mobilisation" to fight the 10% unemployment rate, Cope, the government spokesman, said.
The government will also tackle the immigration issue, "an area that the French have not stopped calling us on", Cope said.
Immigration will fall under the domain of Nicolas Sarkozy, the new interior minister and number two.
Sarkozy said repeat offenders
were also a top priority
He was off to a fast start on Friday, heading to Perpignan where two communities, Gypsies and North Africans, have been in a standoff for days.
Sarkozy, who served as a law-and-order interior minister in an earlier government, said in a television interview on Thursday night that repeat offenders and crime victims also were priorities.
Villepin's streamlined government of 31 ministers includes 23 who had figured in the outgoing team, which had 40 members.
Chirac decided to replace Jean-Pierre Raffarin as prime minister after the stinging defeat on Sunday's referendum on a European Union constitution. The victory of the "no" camp was seen as a sanction against the government.
Chirac dismissed his foreign minister Michel Barnier, replacing him with former health minister Philippe Douste-Blazy, a newcomer to the world of global affairs.
But many key ministers stayed in place, including Defence Minister Michele Alliot-Marie, Finance Minister Thierry Breton and Social Cohesion Minister Jean-Louis Borloo, prompting scepticism from the press and jeers from the left.
The 31-member cabinet, plus de Villepin, has a dozen fewer members than the outgoing government of Jean-Pierre Raffarin.
"Nine new ministers
is not exactly a clean sweep"
French financial daily
"Nine new ministers is not exactly a clean sweep," the financial daily La Tribune said in a commentary.
"Chirac locks down," read the headline of the popular daily Le Parisien, while the left-leaning Liberation went for a play on words with "Sarkommence", meaning "Here we go again", accompanied by a blurry photo of a smiling Sarkozy.
In an editorial entitled "Plastering over", Liberation lashed out:" In the menage-a-trois that is now ruling the country, Nicolas Sarkozy is the one wearing the pants. Never has a minister been so powerful."
In a major climbdown for Chirac, the president - whose confidence rating has plummeted to an all-time low of 24% - allowed his arch-rival Sarkozy to remain as head of the ruling Union for a Popular Movement (UMP).
Sarkozy has made no secret of his desire to replace the 72-year-old Chirac at the Elysee in 2007, and also has a difficult relationship with de Villepin, who has long been the president's loyal lieutenant.
Although the prime minister and his number two have pledged to work together to reunite a deeply divided nation, many wondered how effective the explosive combination will be.