WASHINGTON — The Supreme Court ruled today that Pennsylvania officials did not violate the free-speech rights of troublesome inmates by keeping secular newspapers and magazines away from them.

Justices, by a 6-2 vote, said the state could use newspapers as incentives to get inmates in a high-security unit to behave themselves.

But Justice Stephen Breyer wrote in Beard v. Banks, 04-1739, that Pennsylvania's win could be short-lived, depending on whether there is another constitutional challenge to the high-security unit's rules.

The decision reverses a ruling by the 3rd U.S. Circuit Court of Appeals but validates a dissent by the high court's newest member, Justice Samuel Alito, who sided with Pennsylvania when he served on the appellate court. Alito did not participate in the argument before the Supreme Court.

Breyer said that "prison officials, relying on their professional judgment, reached an experience-based conclusion that the policies help to further legitimate prison objectives."

The high court's ruling could have affected prison operations nationwide if justices had required state officials to prove that their policies serve legitimate security and rehabilitative interests.

The Bush administration sided with Pennsylvania, saying the state's policy deserves deference from the courts because it involves maintaining order in prisons.

In a dissent, Justice John Paul Stevens said a trial should be held to determine whether Pennsylvania's goal is legitimate, especially because of the rights at stake.

"Plainly, the rule at issue in this case strikes at the core of the First Amendment rights to receive, to read and to think," Stevens wrote.

The case involved a high-security segregation unit that Pennsylvania created for inmates who failed to follow prison rules.

Inmates in that unit were permitted access to religious newspapers, two paperback books of general interest, their legal documents and letters from family. If the 40 or so inmates housed there behaved, state officials said the prisoners could regain the privilege of receiving secular newspapers and magazines.

Religious and civil liberties groups had argued that fundamental rights, such as freedom of speech, are not mere privileges that can be granted or revoked at the whim of a prison official. They worried that prison officials would not stop with newspapers but may one day bar access to the Bible.

The case began in October 2001 when Ronald Banks filed a civil rights lawsuit on behalf of himself and other inmates in the disciplinary unit, then located in Pittsburgh, after prison officials barred him from receiving The Christian Science Monitor, a nonreligious daily newspaper.

By a split vote, a three-judge 3rd Circuit panel sided with Banks, ruling that prison officials had failed to show the policy had any effect on inmate behavior. This finding was reversed in today's Supreme Court ruling.