The Justice Department is revising sharply criticized prosecution guidelines for corporate crime investigations, but the changes do not appear to satisfy many of those who led a vocal campaign contending that the existing rules were discouraging corporate officials from holding frank discussions with their attorneys.

The deputy attorney general, Paul McNulty, announced the changes yesterday in Manhattan at a conference sponsored by a legal group, Lawyers for Civil Justice.

“The best corporate prosecution is the one that never occurs,” Mr. McNulty said, according to a prepared text released by the Justice Department. “Through successful corporate compliance efforts, investor harm can be avoided. Corporate officials must be encouraged to seek legal advice if they are in doubt about the requirements of the law.”

The lightning rod for the battle was a policy issued by one of Mr. McNulty’s predecessors, Larry Thompson, in the wake of the Enron and WorldCom implosions. The 2002 document, which has come to be known as the Thompson Memorandum, said prosecutors considering charges against a company could take into account the firm’s willingness to waive attorney-client privilege as well as other factors, such as whether a company was paying legal fees for employees accused of wrongdoing.

The new policy says a company’s refusal to waive its legal privileges will not be held against it, although an agreement to do so could help a company avoid indictment. Payment of legal fees will no longer be a factor, unless there is evidence of a broader effort to impede an investigation.

Mr. McNulty acknowledged that the changes were made in response to the outcry from the legal and business communities. Now, he said, the Justice Department wants lawyers to follow through on their pledge to keep companies in line.”We expect corporate counsel to insist on compliance with the law,” he said. “The American public cannot afford another round of corporate scandals. We rely on you to help us ensure it does not happen again.”

While Mr. McNulty called on corporate lawyers to “stand up” against company officials engaged in wrongdoing, he stopped short of asking attorneys to report wrongdoing to law enforcement or the public.

Senator Specter, a Pennsylvania Republican who introduced legislation last week that would have forbidden federal prosecutors from seeking the contents of privileged attorney-client materials, had no immediate response to the changes announced yesterday.

Senator Leahy, a Democrat of Vermont who is to become chairman of the Judiciary Committee next month, had a lukewarm reaction to the changes. He said he was pleased that the agency responded to its critics, but he added, “I remain concerned that, depending on how the new policies are implemented, prosecutors may still be able to inappropriately consider a corporation’s waiver of this important privilege.”

A spokesman for the U.S. Chamber of Commerce, Peter Lawson, applauded the changes but said they fall short of resolving all the problems caused by the existing rules. He said the balancing of companies’ rights at the pre-indictment stage is more critical than that of individual defendants because the charge itself can be a death knell for a firm. “The indictment’s the whole ball of wax,” the spokesman said. “There’s essentially no recovery from that.”

Mr. Lawson said it was unclear how much benefit would result from the Justice Department’s new position that a company’s refusal to waive the privilege wouldn’t be a negative but agreeing to waive the privilege could help a company escape charges. “It still treats one company more favorably for waiving attorney-client privilege than one that does not. That’s the whole point of this,” he said.

A senior Justice Department official, who spoke with reporters yesterday on condition of anonymity, said it would have been unrealistic to bar any consideration of privileged material. “It our mind it just represents a level of common sense,” the official said of the new policy.”It would be strange and frankly not consistent with our experience for a corporation to decide to provide material considered highly sensitive and highly important and then not want that to be in the balance as an important factor for them.”

The official said his department had “some dispute” with the claims about widespread prosecutorial intrusions into privileged discussions, but that the sense that such an assault was under way did seem to have inhibited the work of corporate lawyers.”To some degree here, perception is the reality,”the official said.

The campaign to change the department’s policy drew a motley set of groups, including the Chamber, the American Bar Association, the American Civil Liberties Union, and the National Association of Criminal Defense Lawyers.