The Supreme Court, in a setback for college basketball coach Jerry Tarkanian, today bolstered the power of the NCAA to discipline its member schools.

The 5-4 ruling also could help the National Collegiate Athletic Association in its effort to police drug use by athletes at state-run member schools.The court said the NCAA, in disciplining Tarkanian, did not violate the constitutional rights of the University of Nevada-Las Vegas coach because the athletic body acted as a private organization, not one operating with governmental authority.

Justice John Paul Stevens, writing for the court, said the university does have governmental power because it is a state-run school.

But Stevens said the NCAA, in seeking to discipline Tarkanian, was acting independently from UNLV.

"The NCAA and UNLV acted much more like adversaries than like partners engaged in a dispassionate search for the truth" in investigating Tarkanian, Stevens said.

The NCAA "is more correctly characterized as an agent of its remaining members, which, as competitors of UNLV, had an interest in the effective and even-handed enforcement of NCAA's recruitment standards," he said.

The ruling's impact on Tarkanian's career at UNLV - or the school's big-time basketball program - was not immediately apparent.

Tarkanian, a highly successful coach who has been at UNLV since 1973, was accused in 1976 of numerous rule violations by the NCAA.

NCAA officials said he arranged for a student to bet a "B" grade without attending class, provided free air fare to a student-athlete, encouraged individuals to give the NCAA false information to impede its probe, falsely certified UNLV's program as being in compliance with NCAA rules and failed to comply with high ethical standards.

The NCAA placed the UNLV basketball program on two years' probation in 1977 for recruiting violations and ordered the university to suspend Tarkanian from coaching for two years.

But Tarkanian obtained a court order blocking the suspension and continued coaching.