VATICAN CITY — Pope Benedict XVI's surprise announcement Monday that he will resign Feb. 28 sets the stage for a succession battle that is likely to determine the future course of a church troubled by scandal and declining faith in its traditional strongholds around the world.

Citing advanced years and infirmity, Benedict became the first pope in six centuries to resign. Vatican officials said they hoped to have a new pope in place by Easter, while expressing shock at a decision that some said had been made as long as a year ago.

Saying he had examined his conscience “before God," Benedict said he felt that he was not up to the challenge of guiding the world's 1 billion Catholics. That task will fall to his successor, who will have to contend not only with a Roman Catholic Church marred by the sexual abuse crisis but also with an increasingly secular Europe and the spread of Protestant evangelical movements in the United States, Latin America and Africa.

The resignation sets up a struggle between the staunchest conservatives, in Benedict's mold, who advocated a smaller church of more fervent believers, and those who feel the church can broaden its appeal in small but significant ways, like allowing divorced Catholics who remarry without an annulment to receive communion or loosening restrictions on condom use in an effort to prevent AIDS. There are no plausible candidates who would move on issues like the ordination of women or ending celibacy for priests.

Many Vatican watchers suspect the cardinals will choose someone with better management skills and a more personal touch than the bookish Benedict, someone who can extend the church's reach to new constituencies, particularly to the young people of Europe, for whom the church is now largely irrelevant, and to Latin America and Africa, where evangelical movements are fast encroaching.

“They want somebody who can carry this idea of new evangelization, relighting the missionary fires of the church and actually make it work, not just lay it out in theory," said John Allen, a Vatican expert at the National Catholic Reporter and author of many books on the papacy. Someone who will be “the church's missionary in chief, a showman and salesman for the Catholic faith, who can take the reins of government more personally into his own hands," he added.

The other big battle in the church is over the demographic distribution of Catholics, which has shifted decisively to the developing world. Today, 42 percent of adherents come from Latin America, and about 15 percent from Africa, versus only 25 percent from Europe. That has led many in the church to say that the new pope should represent a part of the world where membership is growing quickly, while others say spiritual vision should be paramount.

But while most of the world's Catholics live outside Europe, most of the cardinals come from Europe, pointing to a central tension: While the Vatican is a global organization, it is often run like an Italian village.

Under normal circumstances, the cardinals would descend on Rome after the death of the reigning pope. In this case, said the Vatican spokesman, the Rev. Federico Lombardi, the pope will carry out his duties until 8 p.m. Feb. 28, with a successor probably elected by Easter, which this year falls on March 31. But he said the timing for an election of a new pope is “not an announcement; it's a hypothesis."

Possible candidates

Already, speculation is rife about who best fills the perceived needs of the church. Cardinal Angelo Scola, the powerful archbishop of Milan, is seen as the strongest Italian contender. A conservative theologian with an interest in bioethics and Catholic-Muslim relations, he is known for his intellect, his background in the same theological tradition as Benedict, his media savvy and his strong ties with the Italian political establishment. Vatican experts laud his popular touch, even if his writings are often opaque.

Cardinal Marc Ouellet, a dogmatic theologian and a Canadian, is widely seen as a favorite of Benedict, who named him head of the Vatican's influential Congregation for Bishops to help select bishops around the world. Critics in his native Quebec said that he was out of step with the province's more progressive bishops, but that is not necessarily a drawback in today's church.

Cardinal Peter Appiah Turkson of Ghana, the head of the Vatican's Pontifical Council for Social Justice, is seen as the most likely African contender for the papacy. Educated in Rome and New York, he is known for his semi- orthodox views on the use of condoms, saying that married couples could possibly use them to prevent infection when one partner is HIV-positive, although he has also defended Benedict's remark that condom use increases the risk of AIDS spreading.

Cardinal Leonardo Sandri, the prefect for the Congregation for Eastern Churches, is an Argentine who would excite the Latin American wing of the church. He is also a skillful Vatican insider who served in the Secretariat of State under John Paul II and knows how to navigate the Vatican's complex bureaucracy, which might make him effective, Vatican experts say.

During the Cold War it would have been a long shot, but for the first time there is talk that an American, Cardinal Timothy Dolan of New York, could be a contender for pope. His deep conservatism combined with a folksy charisma make him popular with the faithful, at a time when the church is focused on “new evangelization."