In claiming executive privilege to shield documents - then releasing them while arguing he didn't have to - Gov. Bob Taft joins other elected officials weakening the little-tested right of governors to keep their communications private, legal experts say.

Taft, a Republican, said he had the right to withhold weekly reports by a cabinet member. Democratic state Sen. Marc Dann sued to get them, saying they were essential to exposing what and when the governor knew about investment scandals that have resulted in some $300 million in losses from the state insurance fund for injured workers.

Last week Taft turned over the documents but said he's not giving up his executive privilege, just forgoing it for this case. The Ohio Supreme Court has not yet decided whether to dismiss the lawsuit because the records were released, or keep it open to rule for the first time in the state on whether such a privilege exists.

''Clearly the governor was on weak ground given that he caved so easily,'' said Mark Rozell, a George Mason University public policy professor who wrote a book on executive privilege.

Other presidents and governors also have turned over disputed documents but not admitted defeat, saying they maintained the right to hide them, Rozell said.

''The sad thing is that they dilute the principle of (executive privilege) by merely using it as a first bid in a negotiating process with those who want access to documents, only to cave in later,'' he said. ''Better not to make the claim in the first place.''

U.S. presidents since George Washington have tussled with Congress over the privacy of their papers, usually related to issues of national security. The right to unfettered and sometimes secret advice from aides is seen as part of the constitutional separation of the executive, lawmaking and judicial branches of government.

Increasingly, governors say they have the privilege, too.

''There has to be a certain amount of confidentiality with regard to personnel matters, matters that are in negotiations - for example, labor negotiations - other confidential matters in terms of my staff being able to communicate candidly and freely so we can operate state government,'' Taft said in a Dayton appearance. That was before he turned over the reports, which largely recorded mundane details about insurance rates, commission meetings and vacation plans.

Past disputes at the federal level usually were worked out informally, said Jonathan Entin, a law professor at Case Western Reserve University in Cleveland. The term ''executive privilege'' didn't get bandied about until the 1950s, and even today the leading court case testing the concept dates from President Nixon's tape recordings in the Oval Office during Watergate. Even that case had to rely on a ruling from Aaron Burr's 1807 treason trial.

''It's an unwritten kind of practice,'' said Entin, who counts Dann among his thousands of law students.

Lawsuits over executive privilege have become more common, he said, maybe because term limits don't allow lawmakers to build the longtime relationships needed for informal resolution of disputes or perhaps because of the growing rancor in American politics.

Democrat Howard Dean is still fighting the release of his gubernatorial records in Vermont, which he'd wanted sealed for 10 years after leaving office. Attorneys for New Mexico Gov. Bill Richardson, a Democrat, are trying to protect his adviser from having to testify in an investigation into state hospitals for the developmentally disabled.

Republican New York Gov. George Pataki declined to appeal a court loss last winter over the release of documents related to a canal-building scandal.

By releasing some documents in the scandal surrounding the Ohio Bureau of Worker's Compensation, Taft weakens his argument to seal more records on that topic, Entin said.

''That doesn't necessarily prevent him from asserting the privilege in turning over some other documents,'' he said.

Because there are so few court cases seeking to define the concept, Entin said, judges in the future will look to what documents governors have already surrendered.

Carrie Spencer is a correspondent for the Ohio Associated Press in Columbus.