Stunned by Tuesday's appeals court decision against The Washington Post in a major libel case, many of the nation's top editors and libel lawyers said yesterday that the court's reasoning could alter radically the way American journalists do business.

A three-judge panel of the U.S. Court of Appeals here revived a jury's decision that The Post libeled former Mobil Corp. president William P. Tavoulareas in a 1979 article that said Tavoulareas "set up" his son in business. In a 2-to-1 decision, the panel ruled that it was "inappropriate" and "improper" two years ago for U.S. District Court Judge Oliver Gasch to overturn the jury's decision after the jurors ruled against The Post.

However, the sharply worded majority opinion -- written by Senior Circuit Judge George E. MacKinnon and joined by Judge Antonin Scalia -- has provoked vigorous protests from editors and First Amendment lawyers. (So far the decision is a binding legal precedent only in the District of Columbia, where the appeals court has jurisdiction. But The Post probably will ask the full Court of Appeals here to reconsider the panel's decision. The matter could reach the Supreme Court.)

First Amendment lawyers yesterday expressed particular concern that the appeals court decision appears to cast a new light on a Supreme Court decision last year, generally regarded as one favorable to the press. Editors and lawyers also criticized the opinion for suggesting that newspapers such as The Post, which emphasize what the court called "hard-hitting investigative journalism . . . or sophisticated muckraking" could be at a special disadvantage when sued for libel by a public figure.

Editors and newspaper lawyers also expressed dismay yesterday that the appeals panel opinion -- from which Judge J. Skelly Wright dissented vigorously -- appears to lean heavily on a memo from a Post copy editor and comments made in The Post's newsroom as evidence that The Post published the story with a reckless disregard for its truth, and in an attempt to "get" Tavoulareas.

As a result of the decision, editors such as Andrew Barnes, editor and president of The St. Petersburg Times, said that his newpaper will be more cautious about reporting on private companies and more careful about what reporters say in the newsroom.

David Hall, editor of The Denver Post, said he will start an education program in his community on the value of a free press. "Also, when we are doing an investigation, I will make sure the lawyers are at my side from the very beginning . . . .," he added.

Newspaper managers from larger papers indicated that they planned to fight the decision and its potential chilling effect on investigative pieces. Saying he was "shocked" by the ruling, A.M. Rosenthal, executive editor of The New York Times, said he will "basically ignore it" and "go out and cover the news as we always have."

Washington Post general counsel Boisfeuillet Jones Jr., said: "We exercise our own standards of care in judging a story [and] we don't accept [the decision] as real at this point."

"If your work was put through this kind of an analysis where your decision at every turn could be interpreted as something against you despite your efforts to be careful and fair, it could have an extreme effect," he said.

Lawyers representing other media clients yesterday raised questions about the appeals court panel's apparent reinterpretation of a 1984 case called Bose v. Consumers Union of U.S. Inc., which had been considered a major victory for the media.

In the Bose case, the Supreme Court ruled that lower courts have a special responsibility to scrutinize libel awards that trial judges and juries give to public figures.

The Bose ruling was crucial for the media because juries often have difficulty understanding the complex law of libel and rule for the individual, according to Henry R. Kaufman, general counsel of the Libel Defense Resources Center in New York City.

"The typical route over the last four years is that the media have lost at trial in three of four cases and then one looks to judges and most often to appellate judges to address what are often the improper and emotionally tainted verdicts in these cases," he said.

But this appeals court panel took another view.

The crucial passage says that neither the Bose decision nor the landmark 1964 libel decision, New York Times v. Sullivan, "suggests that a district court or a court of appeals is to substitute its assessment of credibility or its general appraisal of the evidence for that of the jury."

Says Bruce Sanford, counsel for the Society for Professional Journalists and Sigma Delta Chi journalism fraternity: "The impact could be enormous. What this two-judge decision has done is undercut the effect of the Bose decision which stated in the strongest possible terms the painstaking task that judges have.

"This says the job isn't that painstaking, isn't that searching, that they don't have to assess the credibility of the evidence," Sanford added.

Sanford said that he and other lawyers believe that reading "stands the Bose decision on its head."

For reporters and editors, many of whom are meeting in Washington this week for the American Society of Newspaper Editors, the most troubling part of the decision was the appeals court panel's opinion that The Post is a newspaper "which seeks, among other things, hard-hitting investigative stories" which should be considered by juries in libel cases.

In the opinion, MacKinnon wrote that "Robert Woodward, [The Post's] assistant managing editor at all times relevant to this case, testified that he regularly conducted staff meetings at which he "describe[d] the kind of stories [he] was looking for" . . . .

Quoting from court transcripts, the opinion written by MacKinnon notes one exchange when Woodward was asked: "In any of these discussions did you ever use a term such as 'I'm looking for something called a holy shit story?' "

Woodward answered in part: "Yes, I did . . . . "

"Regardless of whether one chooses to characterize this policy as conducive to 'hard-hitting investigative journalism' or (to borrow Chief Justice Warren's description . . . ) 'sophisticated muckraking,' it certainly is relevant to the inquiry of whether a newspaper's employes acted in reckless disregard of whether a statement is false or not," the majority said.

In a note on this section, the two judges added that "we are not suggesting that there is something wrong with aggressive investigative reporting . . . . Newspapers provide a vital service by acting as watchdog for the public."

"What they seem to be saying is that if you're a certain kind of newspaper, then you are more likely to be guilty of libel," Rosenthal of The New York Times said.

"What they're describing here is a good newspaper," he added, later saying that he considered the decision "garbage."

And some editors and lawyers are concerned about a section of the opinion that seems to suggest that former Mobil president Tavoulareas might not have been a "public figure" under the terms of the Sullivan decision.

"Although they did not quite reach that conclusion, they said it was not clear, that he might not be," said Floyd Abrams, a prominent First Amendment lawyer in New York City.

Under libel law, a public figure who sues for libel must prove not only that the publication is false, but also that it was published with "reckless disregard" for whether it was true or false or with "malice," as it is called in most courts.

Media lawyers and journalists found their only solace in Judge Wright's dissenting opinion, a view they hope may be shared by a majority on the full Court of Appeals.

"In my judgment, we do not sit, even in reviewing a libel verdict, as some kind of journalism seminar, offering our observations on contemporary journalism and journalists," Wright wrote. Saying he had "no doubt" that the Constitution protected The Post's right to print the story on Tavoulareas and his son, Wright added that if the jury's verdict is upheld "on these mundane, flimsy facts," newspapers will "steer clear of unpleasant news stories," create a "class of untouchables" who cannot be subjects of such stories, and abandon what the Sullivan decision called the "profound national commitment to the principle that debate on public issues should be uninhibited, robust, and wide open."