PORTLAND — Bishop Richard Malone, who oversees the Catholic Church in Maine, is leaving to become the bishop in Buffalo, N.Y., the church announced Tuesday.

Malone will be installed Aug. 10 at St. Joseph Cathedral. It could be a year before Pope Benedict XVI names a new bishop for the Portland Diocese, which covers Maine, according to the church.

In a written statement, Malone said, “There is sadness in my heart at leaving the Catholic faithful of Maine, especially the priests, deacons, consecrated religious, seminarians and lay leaders.” But he said he looks forward to taking on responsibility as chief shepherd in Buffalo, a diocese that has 633,000 Catholics, more than three times the number in Maine.

Buffalo has 32 Catholic churches, seven Catholic colleges and universities, and 15 Catholic high schools. Maine has three Catholic high schools, two in Portland and Saint Dominic Academy in Auburn.

Malone was a familiar sight in Lewiston-Auburn. Don Fournier, principal of Saint Dominic Academy, said he was disappointed to learn Malone is leaving.

Malone didn’t just oversee Catholic schools, he immersed himself in Catholic education. Fournier called Malone a teaching bishop.

“He gave so much time, energy and effort to being with the kids,” Fournier said. “He’d come up once a month. He’d meet every class” and make time for students. “He was an education priest. He was very personal. He gave a great message. Students took in what he said. He always has an angle. He’d pick up on what’s going on.”

Malone marked the start of school each September by celebrating Mass with students. In 2010 he told students the word for the school year was “amnesia, as in don’t get amnesia when it comes to what you’ve learned about God.”

Malone was realistic with his flock and positive.

In February 2010, when news was out that some Catholic schools in Lewiston would close, Malone stood before a packed school gymnasium, a warm smile on his face. He announced St. Dominic Regional High School would become “Saint Dominic Academy,” and elementary schools would be consolidated into the academy.

“I take great joy in announcing Saint Dominic Academy, that’s why you see balloons around here,” Malone said. In other parts of the country meetings like that are held with no balloons because communities are left with no Catholic schools, he said.

Jim Boulet, who attends Holy Family Church in Lewiston, said he too will miss Malone. Boulet, the admissions director and religion teacher at Saint Dominic Academy, often called religion teachers from Maine’s three Catholic high schools. “I will miss his professional guidance,” Boulet said.

He said he also likes the bishop’s leadership style. “He’s very much concerned about evangelism,” helping Catholics who have been away from the church.

Boulet said he liked how Malone promoted a new Catholic radio station, “The Presence” on 106.7 FM. On that station listeners can hear the bishop praying throughout the day and pray along, Boulet said. “It’s nice to have.”

On Tuesday in Buffalo, N.Y., Malone appeared in a press conference with outgoing Bishop Edward Kmiec shortly after Pope Benedict announced Malone as Kmiec’s successor.

As required by the church, Kmiec submitted his letter of resignation when he turned 75 last June 4. It’s customary for the pope to defer acceptance until a replacement is chosen.

Malone introduced himself, promising to listen and learn while speaking out against laws that church leaders believe violate religious freedom. “I come to you happy and without hesitation,” Malone said, praising Kmiec’s leadership in the western New York diocese.

During eight years in Buffalo, Kmiec oversaw a major reorganization that reduced the number of parishes from about 275 to 164 to reflect a declining number of worshippers.

The Diocese of Portland, which encompasses all of Maine, has seen similar restructuring, Malone said, and has about 65 parishes compared to 135 eight years ago.

In Buffalo, Malone said his first priority would be to listen and learn about the diocese. Beyond that, he said he would welcome back absent Catholics, work to strengthen the resolve of the faithful, and speak up for religious freedoms and the church’s right to define itself, which, he said, is the main priority for all of the nation’s bishops.

The bishops have been particularly vocal against a mandate in the Obama administration’s health care overhaul that requires employers, including most religious nonprofits, to provide health insurance that includes birth control for workers. The White House has offered a compromise that would have insurers bear the cost of the birth control instead of religious employers, but the bishops argue it doesn’t go far enough.

“What’s at stake here is something of concern not just to Catholics, but to Jews, Muslims, people of other Christian traditions,” Malone said, “and really it’s an American issue if you believe that religious freedom is our first freedom.”

Among other priorities, he said, would be to work to gain respect for human life from conception to death and for marriage as an institution between a man and woman. New York legalized same-sex marriage last year.

Malone, a native of Salem, Mass., and a lifelong New Englander, was ordained in 1972.