After years of fending off administration attempts to undercut the Freedom of Information Act, two ranking Democrats on the House Government Operations subcommittee on information proposed yesterday what they called "a bold agenda" for strengthening the law instead of weakening it.

"The time has come to assert the public interest over administrative license," Rep. Gerald D. Kleczka (D-Wis.) said in introducing a bill designed to increase the flow of information under the statute.

He said government agencies have too often taken advantage of vaguely worded exemptions, time-consuming delays and unfair fees to prevent the disclosure of records that ought to be made public.

"The current administration," Kleczka said, "has proven particularly adept at this."

Joining him in sponsoring the bill was Rep. Glenn English (D-Okla.), the subcommittee chairman.

The measure was developed and backed by the Society of Professional Journalists (Sigma Delta Chi), whose spokesmen described it as an effort to "preserve the original intent" of the 19-year-old law.

An administration-backed bill to restrict FOIA and make more records secret is currently awaiting hearings in the Senate Judiciary Committee.

The new proposal goes in the opposite direction. It includes a new section explicitly prohibiting the withholding of documents "in order to conceal violations of law, inefficiency, or adminstrative error by an agency."

It would also shift supervision of agency compliance with the law from the Justice Department to the archivist of the United States, who would have the power to issue binding interpretations and advisory opinions.

The Justice Department under both Presidents Jimmy Carter and Reagan has been the font of proposals to restrict the FOIA, and defenders of the act say the department has been perhaps the greatest obstacle to effective administration.

Other sections of the bill are designed to restore the so-called public interest "balancing test" for the release of national security information, to eliminate most of the secrecy currently accorded "internal personnel rules and practices," and to restrict the present exemption for records concerning banks and other financial institutions.

Also, standard fee schedules would be imposed throughout the government, federal courts would be empowered to impose $25-a-day fines for unwarranted delays, and the law would be broadened to cover the White House, the Smithsonian Institution and other agencies now beyond its reach.

Sigma Delta Chi spokesmen say the bill represents the first attempt in years to make FOIA more effective and focus attention on what it does in opening up government activity to public scrutiny.

Enacted in 1966, the law was largely ineffective until Congress enacted amendments in 1974 that made it enforceable and effectively applied it for the first time to agencies such as the FBI and the CIA. Government agencies have been complaining about it ever since.