The American Bar Association today endorsed enactment of an FBI charter with greater restrictions in some areas than proposed by the Carter administration or the FBI.

The ABA's position, expressed by its ruling House of Delegates, is considered to have great weight in Congress, where the charter faces continued controversy. The proposed charter is the first attempt to define the limits of FBI inquiries in order to prevent the kind of abuses exposed over the past decade.

Major modifications in the administration's proposal suggested today by the ABA would further restrict FBI authority to probe peaceful public demonstrations, to engage in unusual covert information gathering techniques and to engage in otherwise illegal undercover activities.

The Aba, which represents 250,000 lawyers, also called for tightening the definition given in the administration proposal of circumstances under which the FBI can look into actions protected by the First Amendment, such as speech and political activity. The ABA suggested that the charter clarify that such investigations must be directed at criminal activity accompanying the activities covered by the First Amendment.

The proposed charter does not cover the foreign intelligence gathering function of the FBI. Rules governing that reportedly are being prepared by Carter administration.

Among the ABA's major recommendations for changes in the administration's proposed charter were:

A proposal for further limits on undercover activities, restricting them to techniques that conform to the constitutional protections against illegal search and seizure, as delineated by the courts. Basically, the recommendation would require that the FBI follow the same standards used to determine whether evidence is admissible in court, even though much of the FBI's work may never be used in a court case.

A recommendation to authorize collecting information about peaceful public demonstrations only when the demonstrations are on federal property or when federal action may be needed to protect the rights of the demonstrators.

A recommendation requiring the attorney general's approval of such activity as going through someone's trash, using devices to record numbers called from a particular telephone, eavesdropping with the consent of one of the parties, and covert photographic surveillance. The association also recommended that the attorney general review all FBI proposals to infiltrate alleged terrorist groups.

In a compromise with the national security committee, which includes many lawyers with intelligence experience, the ABA did not consider a proposal to put teeth in the charter by allowing individuals to sue the FBI for charter violations.

The ABA also approved, "in principle," changes in procedures for dealing with "graymail" -- situations where the government is reluctant to pursue a prosecution because the defendants threaten to reveal national security secrets. Such situations increasingly have arisen in recent years when the government has sought to prosecute violations relating to national security.