A special court that oversees sensitive law enforcement surveillance forced Attorney General John Ashcroft to change his guidelines for FBI terrorism searches and wiretaps, according to documents released Thursday.

The U.S. Foreign Intelligence Surveillance Court, which has not publicly disclosed any of its rulings in nearly two decades, rejected some of the Ashcroft guidelines in May as "not reasonably designed" to safeguard the privacy of Americans.

The Justice Department quickly amended its guidelines and won the court's approval. Nevertheless, Bush administration officials said Thursday they have appealed the restrictions, arguing that the new limits inhibit the sharing of information between terrorism investigators and criminal detectives.

Justice Department spokeswoman Barbara Comstock said the court has severely hampered the use of a broad anti-terrorism law that expanded the government's power to monitor people when terrorism is suspected.

"They have in our view incorrectly interpreted the Patriot Act, and the effect of that incorrect interpretation is to limit the kind of coordination that we think is very important," Comstock said.

The Justice Department declined to release a copy of the appeal Thursday night to reporters. Officials said it was coincidence that the appeal was filed the same day the court made its ruling public.

The court also disclosed the FBI acknowledged making more than 75 mistakes in applications for espionage and terrorism warrants under the surveillance law, including one instance in which former Director Louis Freeh gave inaccurate information to judges.

"How these misrepresentations occurred remains unexplained to the court," the special court said.

The court's May 17 orders, signed by U.S. District Judge Royce Lamberth, were disclosed Thursday to the Senate Judiciary Committee, which has raised questions about the Justice Department's use of wiretap laws in espionage and terrorism cases.

The court, now headed by U.S. District Judge Colleen Kollar-Kotelly, said it intended separately to publish the rulings and promised similarly to disclose any future unclassified orders.

Ashcroft's instructions in March, in a memorandum to FBI Director Robert Mueller and senior Justice officials, made it easier for investigators in espionage and terrorism cases to share information from searches or wiretaps with FBI criminal investigators.

But the surveillance court, which approves requests during secret deliberations, found that Ashcroft's rules could allow misuse of information in criminal cases, where prosecutors must meet higher legal standards to win approval for searches or wiretaps.

"These procedures cannot be used by the government to amend the (surveillance) act in ways Congress has not," the court wrote. In its rare public rebuke, it said the Justice Department spent "considerable effort" arguing its case, "but the court is not persuaded."

Ashcroft had argued that, under changes authorized by the USA Patriot Act, the FBI could use the surveillance law to perform searches and wiretaps "primarily for a law enforcement purpose, so long as a significant foreign intelligence purpose remains."

The Patriot Act, passed late in 2001, changed the surveillance law to permit its use when collecting information about foreign spies or terrorists is "a significant purpose," rather than "the purpose," of such an investigation. Critics at the time said they feared government might use the change as a loophole to employ espionage wiretaps in common criminal investigations.

"The attorney general seized authority that has not been granted to him by the constitution or the Congress," said Marc Rotenberg, head of the Washington-based Electronic Privacy Information Center.

In a follow-up order also disclosed Thursday, the court accepted new Justice guidelines amending Ashcroft's instructions. The court also demanded to be told about any criminal investigations of targets under the surveillance act and about discussions between the FBI and prosecutors at Justice.

"The first Ashcroft order sort of snugged up against the new line that was being drawn, and that may not have been prudent," said Stewart Baker, an expert on the law and former general counsel at the National Security Agency. "You might be able to justify it legally, but I can see why the court would have reacted badly."

Stewart called the surveillance law "a pretty heavy-duty weapon."

Critics have worried that the surveillance court is too closely allied with the government, noting that judges have rarely denied a request under the 1978 law. But the newly disclosed court's orders indicated irritation with serious FBI blunders in 2000 and 2001.

The court said the FBI admitted in September 2000 to mistakes in 75 wiretap applications, including then-FBI Director Freeh's erroneous statement to judges that the target of a wiretap request wasn't also under criminal investigation.

The court also noted that in March 2000, information from espionage wiretaps in at least four cases was passed illegally to FBI criminal investigators and U.S. prosecutors in New York. Clearly frustrated, the court said it barred one FBI agent from appearing before it.

The FBI admitted more recently, in March 2001, that it inappropriately shared surveillance information among a squad of agents, the court said.