The decision was hailed by attorneys for former investment banker Frank Quattrone, who is appealing a conviction for obstruction of justice, and former Enron Chief Executive Jeffrey Skilling, who faces fraud, conspiracy and other charges. Mr. Skilling, whose trial is scheduled to start in January, has pleaded not guilty.

Going forward, the opinion could pose a challenge for the government when it comes to applying the 2002 Sarbanes-Oxley corporate-reform law. That law, passed in the wake of scandals at Enron and other companies, replaced the law used to prosecute Andersen and in part was aimed at preventing the kind of document destruction that occurred there. It imposes stiff criminal penalties on anyone who obstructs or interferes with a government investigation by knowingly altering, destroying or concealing documents, and requires that auditors retain work papers for a period of five years.

Though the court said its ruling affected the earlier statute, the decision "definitely raises some questions about how [Sarbanes-Oxley] provisions are going to be interpreted," said Russell Ryan, a partner at King & Spalding and a former assistant director of enforcement at the Securities and Exchange Commission. Mr. Ryan said the court seemed to recognize that companies need document retention policies and that innocently complying with those policies "is generally a perfectly legal thing to do."

Indeed, the court made clear that lawyers and executives have some latitude in destroying sensitive or outdated documents. " 'Document retention policies,' which are created in part to keep certain information from getting into the hands of others, including the government, are common in business," the court observed. "It is, of course, not wrongful for a manager to instruct his employees to comply with a valid document retention policy under ordinary circumstances."

The opinion "doesn't clearly define what's going to be right or wrong in a document retention policy," said Ellen Podgor, a law professor at Georgia State University. But, she said, it does send a warning to prosecutors: "You have to go after the actual charges you were investigating, you can't use obstruction of justice as a shortcut," in the expectation that proving a defendant interfered with an investigation would be easier than proving the underlying criminal allegation.

Andersen's June 2002 conviction in a Houston federal court -- which led to a $500,000 fine and five years of probation -- hinged largely on advice in October 2001 from an in-house attorney, Nancy Temple, to David Duncan, head of Andersen's Enron team. Mr. Duncan had reservations about some of Enron's planned disclosures in its third-quarter earnings release. In response, Ms. Temple instructed him to delete her name from the memo and to delete references to having consulted Andersen's legal team about the matter.

That email exchange was seen as encouraging document destruction. Jurors used it and other messages urging compliance with Andersen's document-destruction policy as the basis of their finding that obstruction of justice had been committed.

The advice came amid escalating news accounts of Enron's problems and the likelihood that an SEC probe would follow. After SEC subpoenas arrived on Nov. 8, 2001, an Andersen official sent an email saying, "No more shredding...we have been officially served." Prosecutors argued that in such a context, Andersen had, in the weeks leading up to that email, broken a law against "knowingly...corruptly persuading" others to destroy evidence.

Andersen countered that there was nothing inherently illegal about the document destruction policy and that since it would have been lawful for Ms. Temple herself to destroy the records, there was no crime in her advising others to do so.

At trial, jurors accepted the government's expansive reading of the statute and the Fifth U.S. Circuit Court of Appeals in New Orleans upheld the conviction.

But it was not a close call for the Supreme Court, which heard the case five weeks ago, on its last day of oral arguments, and rendered its opinion well ahead of other cases argued months earlier. At argument, the justices were uniformly skeptical of the government's position, which Justice Antonin Scalia called "weird."

"It doesn't make any sense to make unlawful the asking of somebody to do something which is, itself, not unlawful," he said during the April 27 hearing.

Yesterday, the Justice Department said it would consider refiling charges against Andersen. Prosecutors believed "the substantial destruction of documents in anticipation of an investigation by the Securities and Exchange Commission violated the law," acting Assistant Attorney General John Ritcher said in a statement. "We remain convinced that even the most powerful corporations have the responsibility of adhering to the rule of law."

Andersen's attorney, Maureen Mahoney of the law firm Latham & Watkins in Washington, a former Rehnquist clerk, said in an interview that she would ask the Fifth Circuit to order an acquittal for the firm. An acquittal would preclude the government from retrying the case.

It also would help protect the former Andersen partners from more than 100 civil lawsuits filed by investors who lost money in the Enron affair. "There are plaintiffs across the country who have been filing pleadings referring to Arthur Andersen as a convicted felon, and they can no longer do that," Ms. Mahoney said.

The current white-collar case with the closest similarities to the Andersen charges seems to be that of Mr. Quattrone, who is appealing his conviction last year on charges he obstructed a government investigation into how initial public stock offerings were handed out. Mr. Quattrone endorsed an email advising the technology bankers to "clean up" their files. The email was sent two days after Mr. Quattrone learned there was a grand-jury probe into the brokerage firm's practices.

"The fact that the court decided the case the way it did and did so unanimously gives Quattrone a real boost," said Mr. Quattrone's appellate lawyer, Mark Pomerantz of Paul Weiss Rifkind Wharton & Garrison.

Mr. Quattrone was convicted of three counts, including the witness tampering statute at issue in the Andersen case. In papers filed with the federal appeals court in New York, his lawyers objected to the jury instructions given by the trial judge, who told the jury, "You do not have to find, and there is no requirement that you find, that the defendant knew that a proceeding was in fact pending or was even about to be initiated at the time of the corrupt persuasion or misleading conduct." The lawyers argued the instruction "permitted the jury improperly to convict without finding any connection between the defendant's conduct and a pending proceeding."

Some attorneys for Enron executives said the ruling would make it harder for the government to win convictions for their clients. Daniel Petrocelli of O'Melveny & Myers, the attorney for Mr. Skilling, said the Supreme Court concluded that the jury in the 2002 Andersen trial had convicted the accounting firm of criminal conduct "absent any showing of criminal intent." He said the matter of criminal intent would be a key issue in the coming trial of the former Enron executives.

But there are also limits on how far yesterday's decision will help the constellation of fallen business stars charged and convicted in recent years.

William M. Sullivan Jr., a former federal prosecutor and now a white-collar defense attorney at Winston & Strawn in Washington said that with the exception of Mr. Quattrone, few high-profile defendants of recent years are likely to benefit directly from the Andersen ruling.

Former Enron Chairman Kenneth Lay, for example, faces trial in January on securities fraud and insider-trading charges, not the witness-tampering count brought against Andersen. Mr. Lay has pleaded not guilty.

There also are limits on how widely the ruling might be used to challenge Sarbanes-Oxley. Randy Mastro, a partner with Gibson Dunn & Crutcher and a former federal prosecutor, said he thought that it still will be hard for executives to challenge the main Sarbanes-Oxley provision that imposes a much greater onus on management to be aware of their legal obligations.

Write to Jess Bravin at jess.bravin@wsj.com¹¹