A shadowy police service that has snooped on the French people for two centuries closed today as France opened a big new security agency that President Sarkozy calls his "FBI à la française".

The 6,000-strong Central Directorate of Internal Intelligence (DCRI), has been created on Mr Sarkozy's orders to modernise the way that France handles terrorism, serious crime and other security threats.

It has absorbed the legendary Renseignements Généraux (RG), the powerful police branch that historically has acted as the eyes and ears of the State, keeping tabs on public opinion and potential troublemakers. Mr Sarkozy — who was chief of national police as Interior Minister until last year — was keen to end the RG's unsavoury tradition of domestic snooping and its notorious use of anonymous tip-offs.

To the displeasure of its traditionalist officers, the RG has been combined with the DST (Department of Surveillance of the Territory), the internal security service, which is like the British MI5 but with police powers, to create an FBI-like agency. The DGSE, the foreign intelligence service, equivalent to MI6, reports to the Ministry of Defence.

Heading the new internal agency is Bernard Squarcini, 52, a police intelligence chief close to Mr Sarkozy who is known as The Shark.

The RG, the biggest police spying network of any democracy, was formed in the Second World Was as successor to agencies dating back to the the Revolutionary terror of the 1790s. It has long been a tool of its political masters, with its officers sounding the public mood in pubs, clubs, canteens and trade unions across the country.

Old-style RG officers see themselves more as reporters than spies, keeping contacts with the local community as well as informers and collecting tipoffs. "A trade is disappearing. We took an interest in the unhappiness of the middle classes and gatherered pub chat," a provincial RG officer complained to Le Monde newspaper today.

Several hundred RG officers have opted to stay on as information specialists with local police but they are unhappy about giving up the old service. "There is a real difference in culture between the RG and the ordinary police," said Dominique Achispon, an official with the Natoinal Police Union and a former RG officer. "At the RG, we work discreetly with the stress on personal relations with unionists, politicians, company bosses. In the police, you are the officer dealing with a complaint or an offender."

Most of the rest have been vetted for handling state secrets and sworn into the DCRI, based in a high-security 387 million euro building at Levallois in northern Paris. An exception has been made for the Paris city RG which will continue for a time in its old form.

Mr Sarkozy, who headed both the RG and DST when he served as Interior Minister, wanted to combine the former's grass roots human skills with the high-calibre intelligence-gathering and enforcement of the latter.

He also wanted to ensure that it stopped informing on political and ordinary life. He had fallen victim to this when Dominique de Villepin, his political rival and the former prime minister, ran the Interior Ministry for a period in 2004. Mr Sarkozy suspected that Mr de Villepin used RG intelligence to smear him.

The domestic spying will not stop, however. The new agency will draw on extensive national security powers to tap communications of all kinds from its high-tech headquarters. It's foot soldiers from the former RG will continue to keep their ears close to the ground in the Islamic community, for example, on the look-out for possible terrorist threats.

Times Recommends

• Heed the great stabiliser’s words
• How a voice for everyone led to stalemate
• Bakara market becomes a slaughterhouse