Attorney General William French Smith yesterday issued new federal guidelines designed to make it easier for the FBI to investigate domestic groups that advocate violence to achieve social or political change.

"We are not waiting for the proverbial ticking to start," Smith remarked. He said the changes are designed to help FBI agents stop terrorist activity before crimes are committed and injuries occur.

The new rules, which go into effect in 14 days, replace strict guidelines issued in 1976 by then-Attorney General Edward H. Levi, following disclosures that the FBI had engaged in widespread spying on Americans, particularly in the civil rights and anti-war movements in the 1960s and 1970s.

In defending the changes, which bring the guidelines for investigating domestic security cases more into line with less restrictive rules for general criminal cases, Smith said, "Our citizens are no less threatened by groups which engage in criminal violence for political or racist purposes than by those which operate lawlessly for financial gain."

The guidelines, which were criticized by civil liberties groups, but only mildly, are not subject to congressional approval. The changes would authorize the FBI to:

* Use informers and infiltration by undercover agents in a preliminary inquiry, before there is enough evidence to warrant a full investigation. Levi had restricted those techniques to full investigations.

* Continue limited monitoring of inactive groups even though the group may pose no "immediate threat of harm." The FBI had been closing such probes when a group went a year without violence.

* Collect and maintain publicly available information on groups not under investigation as long as it does not violate the privacy act.

* Conduct full investigations based solely on public statements advocating crime or violence when there is an apparent intent and capacity to act on the threat.

* Investigate members of front or support groups that knowingly help the criminal objectives of a group already under investigation.

Smith said the new guidelines "will clarify the standards governing these investigations and reaffirm the importance of gathering criminal intelligence about violence-prone groups, while retaining adequate protections for lawful and peaceful political dissent."

FBI Director William H. Webster, who joined Smith for the announcement, said that many FBI agents have been reluctant to open domestic security investigations because of the likelihood of lawsuits claiming a violation of constitutional rights.

"There's a general pattern in the field of agents preferring bank robberies or other general crime" rather than domestic security cases, Webster said. "There's a concern about personal liability by the agents, a tendency to tack in and out of these investigations without being as thorough as we need to be."

Webster said the FBI will not return to the days before the Levi guidelines, when the bureau was involved in 4,686 domestic security investigations, compared with 73 last year.

"I don't see us as . . . penetrating political groups . . . but instead groups engaged in or created for the purpose of commiting crimes."

The American Civil Liberties Union, however, expressed concern over the new rules.

"Unless narrowed or clarified, the FBI may slide back into the business of monitoring those who engage in merely heated debate or advocate unpopular activity," ACLU official Jerry Berman said in a statement. "We need some clarification."

Berman said the changes ignored recent recommendations of a Senate committee investigating the FBI's Abscam operations, which urged the FBI to require a "probable cause" standard of evidence before allowing undercover operations in any investigation.

Rep. Don Edwards (D-Calif.) chairman of a House subcommittee on civil and constitutional rights, also raised concerns about allowing the FBI to start an investigation based simply on what a person advocates. He asked a Justice Department official to appear before his panel to explain the guidelines.