WASHINGTON — Public colleges and universities can use money from mandatory student-activities fees to finance campus groups that engage in political speech some students find objectionable, the Supreme Court ruled today.

The court voted unanimously in Board of Regents of the University of Wisconsin System v. Southworth to uphold the University of Wisconsin's student-fee system, which the justices said does not violate any student's free-speech rights.

Had the justices ruled the other way, public colleges and universities across America would have had to stop giving money to controversial student groups or figure out some way to give partial refunds to those students who wanted them.

'The First Amendment permits a public university to charge its students an activity fee used to fund a program to facilitate extracurricular student speech if the program is viewpoint neutral,' Justice Anthony M. Kennedy wrote.

He added: 'When a university requires it students to pay fees to support the extracurricular speech of other students, all in the interest of open discussion, it may not prefer some viewpoints to others.'

Three of the court's nine members joined in upholding Wisconsin's fees but refused to join the decision's language requiring viewpoint neutrality.

'I agree that the university's scheme is permissible but do not believe the court should take the occasion to impose a cast-iron viewpoint neutrality requirement to uphold it,' Justice David H. Souter wrote in an opinion joined by Justices John Paul Stevens and Stephen G. Breyer.

When Wisconsin's student-fees system was challenged in 1996, about $15 of the $166.75 students paid in fees each semester was earmarked for distribution to campus groups by the student government. For a school with some 38,000 students, that created a total fund each semester of about $570,000.

Several law students with conservative political views objected to having some of their money funneled to liberal organizations. Their lawsuit identified as objectionable 18 of the 125 subsidized campus groups, including the Lesbian, Gay, Bisexual and Transgender Center and International Socialist Organization.

Scott Southworth, the lead plaintiff and now an attorney, said in a recent interview, 'As a conservative and a Christian, it was frustrating to see the money going to organizations I personally disagree with.'

A federal judge and a federal appeals court ruled against the university, but the nation's highest court said they were wrong.