The director of the Federal Bureau of Investigation (FBI), Robert Mueller, has proposed the creation of an intelligence service within his organization and repeated his opposition to calls for a new and separate domestic spy agency.

Mr. Mueller told members of the U.S. Congress he supports what he called the creation of a service within a service, reorganizing but keeping domestic intelligence responsibilities within the FBI.

He says this is necessary so agents can act quickly to stop terrorist attacks against targets within the United States.

"We must continue to integrate intelligence and law enforcement operations," he said. "We must be able to employ both intelligence and the criminal tools as part of the integrated counterterrorism strategy that gives us the flexibility to move quickly from intelligence gathering to disruption at a moment's notice."

Some members of Congress have questioned whether an agency devoted for decades to law enforcement can make intelligence a mission of at least equal importance.

One proposal would set up an organization similar to Britain's security service, known as MI5, which collects, analyzes and disseminates intelligence aimed at disrupting terrorism, espionage and sabotage against Britain.

Mr. Mueller has worked hard against the idea of an independent, domestic, intelligence agency. Former FBI Director Louis Freeh, current Attorney General John Ashcroft, his predecessor Janet Reno and George Tenet, who resigned Thursday as CIA director, have all recommended against a new homeland spy agency.

The CIA is responsible for U.S. intelligence operations overseas.

The FBI director told members of Congress a separate organization for domestic intelligence gathering would lead to needless duplication.

"If you wish to establish another agency, you have to replicate a number of the pieces of the bureau that contribute to the ability to anticipate and disrupt another attack," he said.

Mr. Mueller said that a new agency would have to duplicate the FBI's surveillance activities and translators, and establish relationships the bureau already has with local law enforcement agencies.

The FBI director proposed that a new directorate of intelligence be established within the bureau with clear authority over intelligence functions.