The Archbishop of Canterbury warned yesterday that the Episcopal Diocese of Los Angeles' election of a lesbian and former Philadelphia priest as a bishop threatens to further divide the worldwide Anglican community.

On Saturday, the diocese's annual convention by a narrow margin chose the Rev. Mary Glasspool, 55, as its next suffragen, or assistant, bishop. If approved by the Episcopal House of Bishops, Glasspool would be the denomination's first openly gay female prelate.

Glasspool, who was assistant to the rector of St. Paul's Episcopal Church in Chestnut Hill from 1981 to 1984, lives in an open relationship with her long-term partner, Becki Sander. Glasspool is currently on the staff of the Diocese of Maryland, where she is Canon to the Bishops.

On Saturday, Glasspool hailed her election as a victory for gay people. "Any group of people who have been oppressed because of any one, isolated, aspect of their person yearns for justice and equal rights," she said.

Ordained in March 1982, she left the five-county Diocese of Pennsylvania to become rector of a parish in Boston and has not served here since.

Although praised by those who know her as "pastoral" and a capable administrator, the Rev. Rowan Williams, Archbishop of Canterbury and head of the Church of England, yesterday urged the Episcopal Church USA not to sanction her ordination.

Glasspool's election "raises very serious questions not just for the Episcopal Church and its place in the Anglican Communion, but for the communion as a whole," he said yesterday.

A majority of the American bishops must ratify any diocese's choice of bishop before ordination may proceed. Glasspool's selection must be approved within 120 days.

In 2003, the bishops approved the Diocese of New Hampshire's choice of Gene Robinson, an openly gay priest of the diocese, as its diocesan bishop.

Robinson's ordination sharply divided the two-million-member American church, and has provoked threats of conservative schism within the 77-million-member worldwide Anglican communion, to which the Episcopal Church belongs.

Williams is symbolic head of the Anglican communion, but he has no authority to bar Glasspool's ordination.

The Rev. Clifford Cutler, current pastor at the 750-member parish of St. Paul's, yesterday praised Glasspool as a "very great, very competent person with a good pastoral sense."

Cutler, who knew Glasspool when she was at St. Paul's and he led a mission church in Kensington, said he believed she would make a "very fine suffragen."

Women clergy were still new in the Episcopal church when she was ordained, he said, "but she made visits to a lot of households" in the parish "and put the people at ease." Cutler said he did not know if she was openly gay at the time.

The Rev. Allison Cheeks, one of the 11 women first ordained to priesthood within the Episcopal Church in 1974, also praised Glasspool yesterday, calling her a "splendid person" and "a first-rate priest."

"I'm delighted this has happened," said Cheeks, 82, who lives in Maine.