Washington ? The Supreme Court threw out the conviction of the Arthur Andersen accounting firm for destroying Enron Corp.-related documents, ruling unanimously Tuesday that the jury instructions were too broad.

The decision was a defeat for the Bush administration, which had declared prosecution of white-collar criminals a high priority following accounting scandals at major corporations. But it offered only symbolic relief for Andersen, the company whose 2002 conviction put 28,000 employees out of work and left it virtually defunct.

“We pursued an appeal of this case not because we believed Arthur Andersen could be restored to its previous position, but because we had an obligation to set the record straight,” Patrick Dorton, Andersen spokesman, said. “We are very pleased with the Supreme Court’s decision.”

The Justice Department said it was disappointed and was reviewing its options, including retrying the case. “We remain convinced that even the most powerful corporations have the responsibility of adhering to the rule of law,” said acting assistant Atty. Gen. John C. Richter.

The high court’s decision was surprisingly swift, coming just over a month after the justices heard arguments in the case.

Chief Justice William H. Rehnquist, writing for the court, said the former Big Five accounting firm’s obstruction-of-justice conviction was improper because the instructions at trial were too vague for jurors to determine correctly whether Andersen obstructed justice.

Enron crashed in December 2001, putting more than 5,000 employees out of work, just six weeks after the energy company revealed massive writedowns. As the Securities and Exchange Commission began looking into Enron’s convoluted finances, Andersen put in practice a policy that called for the destruction of what it considered unnecessary documentation.