WATERVILLE, Maine — The Rev. Dr. Robert Grove-Markwood was installed Saturday as the 11th and final president of Bangor Theological Seminary during the opening of the school’s last convocation at First Congregational Church, United Church of Christ.

Grove-Markwood’s tenure will be the shortest of any president. He said Thursday that he would serve one year at the helm of the 198-year-old institution before the seminary becomes a very different kind of institution from what it has been for the past two centuries.

He will oversee the institution’s transition from a degree-granting seminary to a much smaller organization most likely dedicated to providing continuing education to ministers, lay leaders and spiritual seekers.

In March, the seminary announced that it would suspend its master of arts and master of divinity programs at the end of the 2012-13 academic year. Grove-Markwood of Presque Isle said Thursday that those programs and its doctor of ministry program would end in May 2013. As a result the seminary could graduate its largest class in recent history next year. More than 40 students are trying to finish up their degrees this year, he said.

“Our past mission has been equipping and supporting persons engaged in ministry,” he said. “I think our future mission, whatever structure, whatever shape the new entity takes, it needs to be clear we are ending all the degree programs, which will have a significant impact on the size of the institution. We will no longer have a full-time faculty and will not need the number of staff that we have. It will be a much smaller institution.”

Associated with the United Church of Christ, the seminary has for nearly 200 years trained ministers and lay leaders in mainline Christian denominations including United Methodists, Episcopalians, Lutherans and Congregationalists.

The school’s future still is unclear, Grove-Markwood said, but is emerging slowly.

Since March, the Third Century Committee has been meeting to determine the seminary’s future since it no longer will offer degrees, Grove-Markwood said Thursday. More than 250 students, alumni, area ministers, denominational officials and community leaders have shared their thoughts about what the future might be.

The timeline calls for a draft plan to be presented in October to the board of trustees with a decision tentatively scheduled to be voted on in November.

With fewer residents of northern New England — where BTS has historically drawn students from and supplied ministers to — praying daily, attending church services regularly and claiming a denominational affiliation, mainline denominations have been losing membership over the past 40 years. Most churches no longer can afford full-time ministers or other staff, Grove-Markwood said Thursday. Consequently, BTS does not have enough potential students to sustain itself in its traditional role.

“This is an historic threshold in the life of Bangor Seminary,” the Rev. Dr. Nick Carter, president of Andover Newton Theological School in Newton Centre, Mass., said Saturday at Grove-Markwood’s installation. “Ten generations after your founding, amid tectonic shifts in the plates that lie beneath theological education, the dreams of your founders are being probed for new inspiration.”

BTS is not the only mainline seminary struggling to redefine itself, Carter said.

“Other than the Gospel itself, almost all of the assumptions on which theological education has been based for the last 200 years are in the midst of being swept away,” he said. “But God has not abandoned us, just as God did not abandon Israel. God still has a dream for us. God still has a dream for this great community.”

That “dream” most likely will be focused on continuing education, the seminary’s newest president said.

Grove-Markwood was named interim president in June 2011, a week after the Rev. Dr. Kent J. Ulery resigned after three years at the helm.

Grove-Markwood has a long history with BTS, having received both master of divinity and doctor of ministry degrees from the institution. He also served as the institution’s director of admissions from January 1985 to June 1987. For the past five years before being named interim president, he was a member of the board of trustees.