America's Roman Catholic bishops voted yesterday to tighten control over the nation's Catholic colleges and universities, implementing a mandate from the Vatican to end decades of unfettered academic independence and secularization.

The proposal, approved overwhelmingly by 255 bishops meeting in Washington, would require Catholic theologians at the institutions to be approved by their local bishops and strongly encourage each college to hire a president and a majority of faculty, staff and board who are "Catholics committed to the Church." While the bishops would have no legal authority or right to hire and fire staff, they would have a formal church procedure to exert pressure on university presidents.

A few of the 235 colleges affected welcomed the proposal, including Catholic University, established in Washington by the American bishops. "Institutions should be eager to be accountable, loyal and faithful," said the Rev. David M. O'Connell, president of the university.

But most of the colleges had opposed the measure. In the year leading up to the debate, the presidents of many Catholic colleges, including Georgetown University, wrote letters and editorials describing the proposal, for example, as "profoundly detrimental" and an "obvious threat to academic freedom."

The bishops softened the document in the last month, noting, for example, that a Catholic university's task is not "to indoctrinate or proselytize its students." But university leaders were not satisfied.

"This is not a document the majority of presidents would have preferred," said the Rev. James L. Heft, chairman of the Association of Catholic Colleges and Universities. "People are concerned it sends out the perception that Catholic universities don't have real and legitimate academic freedom."

Concerns ranged from matters of pride to practicality. Presidents worried schools would lose prestige if they were perceived as religiously narrow-minded. They also worried the mandate would jeopardize government funding many Catholic colleges depend on, discourage non-Catholic faculty from applying, and open the schools to discrimination lawsuits.

The proposal is a response to Pope John Paul II's 1990 decree, "Ex Corde Ecclesiae," asking bishops worldwide to rein in their local Catholic institutions by reasserting a formal oversight role. The American bishops passed a less rigid proposal in 1996, but the Vatican rejected it as too loose. The latest version would take effect only after the Vatican approves it.

The document leaves unclear exactly what consequences the universities--which do not receive funding from the Vatican--could face for failing to abide by the new rules. Conceivably, a bishop could disavow a university's Catholic affiliation, or declare its president in violation of canon law.

Georgetown University, which severed its formal links with the church in the 1960s and has since shed many of its most obvious Catholic trappings, released a muted statement yesterday.

"We embrace our Catholic and Jesuit identity and our commitment to academic excellence," said Rev. Leo J. O'Donovan, president of the university, and "welcome the call of Pope John Paul II and the American bishops to strengthen these mutually sustaining dimensions of our educational mission."

But Rev. John P. Langan, who teaches Catholic social thought at Georgetown and recently briefed the faculty on the impact of the document, was more wary.

"It puts us into a period of great uncertainty," he said. "We're on uncharted water in many ways."

One of the document's most controversial elements requires theologians to seek a "mandatum," or formal approval, testifying that he or she "teaches within the full communion of the church."

Bishop John J. Leibrecht of Springfield, Mo., chairman of the committee that wrote the document, and others described the rules as "flexible" and "benign," and said rejection would be rare. The mandatum would not be an "inquisition," with an "intensive, intrusive" review of their writings, said Cardinal Anthony Bevilacqua, archbishop of Philadelphia.

But others worried the rules left leeway for "capricious" actions by overly vigilant bishops, said the Rev. Daniel E. Pilarczyk, archbishop of Cincinnati. While some bishops would approve theologians easily, others might pry.

"I really believe passage now would create a true pastoral disaster," said the Rev. Rembert Weakland, archbishop of Milwaukee and the only one to speak forcefully against the document. "The tension between the hierarchy and theologians is the greatest I've seen in my 36 years of being a superior. If we move ahead, they will be extremely defensive."

Others expressed concern that such close ties to the bishops might jeopardize the government funding many institutions depend on. Many states, especially in the West, "have very restrictive constitutional provisions" prohibiting states from funding religious education, said Charles Wilson, an attorney who has represented Catholic universities. He noted that the American Civil Liberties Union has challenged state funding for a Jesuit university in Washington state.

Other concerns stemmed from the recommended quota of Catholic faculty and expectation that they follow church doctrine. Presidents worried the rules would set up a two-tier system: Catholics at the university would be held to a higher standard, with presidents taking an oath of fidelity and other Catholic faculty promising to remain "committed to the church." Non-Catholic staff, meanwhile, would feel marginalized, and might be pushed to sue.

"If someone on the faculty is about to lose a position, or not get tenure, this rule gives them something to point to as a discriminatory criteria," said Wilson.