CHICAGO — A federal appeals court ruled yesterday that the Southern Illinois University School of Law should reinstate a Christian group whose student organization status had been revoked because members must pledge to adhere to Christian beliefs.

The 2-1 ruling by the U.S. 7th Circuit Court of Appeals reverses a district court judge's decision last July that denied Christian Legal Society a preliminary injunction that would re-establish the group's status while its lawsuit against the university proceeds.

Christian Legal Society sued SIU in April 2005 after the university revoked the group's registered status, meaning it no longer could use the university's facilities or name and wasn't eligible for school funding. The group claimed SIU's decision violated its First Amendment rights to free speech and free exercise of religion.

SIU said the society's requirement that members adhere to basic Christian beliefs violates the school's affirmative-action policy as well as a Board of Trustees policy stating that student organizations must follow all "federal or state laws concerning nondiscrimination and equal opportunity."

But in yesterday's ruling Christian Legal Society v. Walker, the appeals court said "SIU failed to identify which federal or state law it believes (Christian Legal Society) violated." The three-judge panel majority also noted that the group's membership policies are "based on belief and behavior rather than status, and no language in SIU's (affirmative-action) policy prohibits this."

Messages seeking comment were left after business hours yesterday for SIU general counsel Jerry Blakemore and Christian Legal Society attorney Casey Mattox.

Mattox has said that SIU began looking into the chapter's requirements after a student who never attended a Christian Legal Society meeting read about its policies in a law journal and brought them to administrators' attention. No student ever was denied a membership or leadership position within the group because of his or her religious beliefs, he said.

Christian Legal Society, based in Annandale, Va., is a nationwide association of more than 3,400 Christian lawyers, law students, law professors and judges with chapters in more than 1,100 cities across the country, according to its Web site. The SIU chapter had fewer than 12 members, Mattox said.

The group has won similar lawsuits against other schools, but lost a suit in April against the University of California Hastings College of Law, which denied it recognition in 2004. A settlement of a similar case with Arizona State University last fall determined that religious student groups at that school can discriminate against those who don't share their religious beliefs but cannot exclude students from membership on the basis of sexual orientation.