The Vatican yesterday ordered an American priest and nun to end their 30-year ministry to gays and lesbians after an investigation concluded that they failed to comply with the Roman Catholic Church's teaching on the "intrinsic evil of homosexual acts."

In a rare direct intervention, the Vatican placed a gag order on Sister Jeannine Gramick and the Rev. Robert Nugent, who have toured the country from their base in Prince George's County, teaching Catholic parishes ways to reconcile church doctrine with the realities of gay life. The decision effectively ends the careers of two of the most prominent gay rights advocates within the Catholic Church.

By issuing a public "notification" calling the pair's teachings "erroneous and dangerous," the Vatican resorted to a level of punishment it has used against American clergy only twice in the last 60 years, both times in the cases of errant theologians. Most recently, in 1986, the Rev. Charles E. Curran, then a professor at Catholic University, was notified by the Vatican that he could no longer teach Catholic theology.

According to the notification, Gramick and Nugent are "permanently prohibited from any pastoral work involving homosexual persons and are ineligible, for an undetermined period, for any office in their respective religious institutions." While falling short of excommunication, a still rarer measure, this notification is considered an extreme punishment, in part because of its public nature. The church more frequently chastises errant clergy with a private letter, or through a bishop. This time, though, it chose a kind of public shaming, broadcasting to parishes across the nation that Gramick and Nugent's views are anathema to the church.

The ruling also sends a message to the growing number of gay outreach and AIDS ministries in Catholic churches to be careful: In showing compassion for homosexuals, they must remember to mention the church's disapproval of homosexual acts. In the months before the decision, several parishes holding gay-themed conferences canceled scheduled talks by Gramick and Nugent.

The highly publicized ruling reflects the church's increased impatience with the growing number of Catholics who call for full acceptance of homosexuals by the church. In 1986, the Vatican issued a statement clarifying its position on homosexuality, reminding Catholics that the church did not consider homosexuality a neutral, or a good, as some had been teaching, but a disorder.

For church reformers, who considered Gramick and Nugent models of moderation, the decision was merely the latest in an escalating series of crackdowns by the Vatican.

"I call it theological cleansing, as in ethnic cleansing," said Sister Maureen Fiedler, head of Catholics Speak Out in Hyattsville, who worked with Gramick in the 1980s. "It's gotten worse and worse over the last few years."

Gramick and Nugent began counseling gay and lesbian Catholics in the '70s, according to friends and colleagues. (Both were traveling back from Rome and could not be reached for comment.) In 1977 they founded New Ways Ministry, an educational and counseling center in Mount Rainier.

Almost immediately their activity drew the suspicion of local church officials, especially Cardinal James Hickey, archbishop of Washington. Hickey met with the pair in 1981 and found their teachings "vague, misleading, and even contrary to Catholic faith," he recalled in a statement yesterday.

While the Vatican recognizes that some people are permanently homosexual -- a concession many conservative Christians do not make -- the church also teaches that homosexuality is a disorder, and that homosexual activity is sinful.

In their teachings and writings, Gramick and Nugent questioned whether homosexuality was a disorder, and said there were certain contexts where homosexual activity was moral. The pair functioned as a kind of traveling teach-in, lecturing mostly straight audiences in hundreds of diocese and Catholic institutions about gay history and sociology, trying to build a grass-roots movement of compassion for what they felt was a much misunderstood segment of fellow Catholics.

In 1984, Hickey, backed by Vatican authorities, told the two to separate themselves from New Ways Ministry and any outreach activities that did not present "the church's teachings regarding the intrinsic evil of homosexual acts."

While the two complied with the order to leave New Ways, they continued to travel across America under the auspices of their religious orders, the School Sisters of Notre Dame and the Salvatorians, spreading the same message in workshops and overnight retreats.

Supporters and critics alike describe the pair as gentle, yet they were persistent to the edge of defiance. In 1992, four years after the Vatican appointed a commission to investigate them, Gramick and Nugent published a book called, "Building Bridges: Gay and Lesbian Reality and the Catholic Church," expounding on their beliefs.

In 1995, their case was turned over to the Congregation for the Doctrine of Faith, the disciplinary arm of the Vatican, run by the much feared Cardinal Joseph Ratzinger of Germany. The congregation twice sent the pair a series of questions designed to clarify their views, but was dissatisfied with the answers.

"Sister Gramick, while expressing her love for the church, simply refused to express any assent whatsoever to the teachings of the church on homosexuality. Father Nugent was responsive, but not unequivocal," reported Ratzinger.

In the end, Ratzinger, with the approval of Pope John Paul II, decided on permanently prohibiting the two from any work involving questions of homosexuality, including teaching and lecturing.

As church officials see it, the Vatican was patient. "Both were given numerous opportunities over the past 20 years to clarify their positions," wrote Hickey.

Gramick and Nugent must now decide between their church and their vocation. Gramick was cooperative in meetings with all the leaders of her order in Rome, according to Sister Jane Burke from the Baltimore province, who flew over with her. But Gramick has not yet decided whether she wants to comply with the ruling. The order will give her a month to make her choice.

CAPTION: Sister Jeannine Gramick and the Rev. Robert Nugent have been teaching parishes ways to reconcile church doctrine with realities of gay life. The Vatican intervention effectively ends the careers of the two gay rights advocates.