FBI Director William H. Webster is proposing sweeping cutbacks in the Freedom of Information Act, it was learned yesterday.

Webster's proposals would empower the FBI to deny files to aliens and to anyone convicted of a felony, would set a seven-year moratorium on releasing investigative information and would exempt from the act foreign intelligence and counterintelligence, organized crime and terrorism.

Webster also formally called for giving the FBI power to withhold information that "would tend to disclose the identity of a confidential source." Under present law, the FBI can refuse to release such information only if it "would disclose" the source's identity.

The proposals are contained in a 44-page booklet plus introduction and appendices. They are dated June 19 and are now circulating in the Department of Justice and House and Senate committees with oversight authority over the FBI.

The proposed amendments to the Freedom of Information Act are certain to be controversial, because the law has led to significant disclosures of intelligence agency abuses, including some by the FBI. Webster said his amendments were prepared at the request of several oversight committees.

Webster said his proposals "do not necessarily represent" the views of the Department of Justice or the administration, and that they "endeavor to refine the act, not to repeal it."