Stung by congressional concerns about the start of a "national, police state," the Justice Department retreated yesterday from its approval of an expanded FBI computer program to exchange information with state and local law enforcement agencies.

Deputy Attorney General Peter F. Flaherty, who approved the request for FBI "message switching" to other agencies on May 19, said, "We have a hold on it now. We are re-examining the authorization. We don't want to violate anyone's civil liberties."

Flaherty's decision was met with cries of alarm by key members of the House Judiciary Committee, especially because a similar request by FBI Director Clarence M. Kelley was turned down last year by then-Attorney General Edward H. Levi after their objections.

Rep. Don Edwards (D-Calif.), chairman of the House Judiciary Subcommittee on Civil and Constitutional Rights, said yesterday that he plans to call Flaherty to a hearing in early July to explain his action.

"We're disturbed that they [Justice Department officials] made a major decision without consulting us," Edwards said. "The subcommitte has strong objections to national intelligence networks. It poses all kinds of spectres."

The project approved by Flaherty would let local and state police departments communicate with each other through the FBI computer system. Opponents fear that such a "message switching" system would be the first step toward a nationwide police computer network at the center of which would be the FBI, monitoring all traffic.

At present, the FBI's computerized National Crime Information Center stores files on wanted and missing persons, six kinds of stolen property and, to a lesser extent, indivdual criminal histories, according to Raymond Young, an NCIC official.

At present, a police in say, Philadelphia, can ask the NCIC computer whether it has in its memory a report that a given car is stolen, and that computer can rapidly come back with a response that, for example, a Los Angeles agency has made such a claim.

What the computer can't do is put the Phildadelphia police in touch with the Los Angeles police for a confirmation that the report is not out-of-date, a false alarm, or otherwise wrong.

That confirmation inquiry must be made by mail or telephone.

Flahertys approval last month would allow FBI-computer system to switch such confirmation messages between the local jurisdictions, on all files except the individual criminal histories, Young said.

It would also allow NCIC to switch messages from Puerto Rico to a separate computer network run by a group of state police agencies, and back and forth between the United States and Canada.

Critics such as Edwards and Rep. John E. Moss (D-Calif.) have expressed concern that the message switching program is a first step in making the FBI a "Big Brother" monitoring all communications between other police agencies.

"This move is not only ill-advised, but poses a bisic threat to the civil liberties and privacy of every citizen," Moss said in a June 8 letter to Attorney General Griffin B. Bell.

Flaherty acknowledged yesterday in a phone interview that he had not consulted with congressional leaders before approving the expanded FBI computer program.

"Perhaps I should have," he said. "I certainly want to talk to Mr. Edwards and Mr. Moss. We're still in the preliminary, exploratory stages on this . . . Nothing has been etched in stone."