PORTLAND — After 14 years at Oregon’s flagship university, Dave Frohnmayer is retiring as president of the University of Oregon.

A well-known name across Oregon, Frohnmayer previously served as the state’s attorney general and ran as the Republican candidate for governor in 1990, losing to Democrat Barbara Roberts.

A native Oregonian, Frohnmayer oversaw the emergence of the University of Oregon as an athletic powerhouse and a building boom on campus, as well as a fundraising campaign, the largest in Oregon history, that’s raised $759 million so far.

Under Frohnmayer, enrollment jumped by about 20 percent to more than 20,000, the university increased its presence in Portland and around the state, and the school started a program that exempts qualified students in lower-income families from tuition and fees.

But he also struggled against state budget cutbacks, complaints over faculty salaries that didn’t match those at peer universities, concerns over his close relationship with the university’s largest donor, Nike founder Phil Knight, and spiraling tuition costs.

Oregon University System Chancellor George Pernsteiner said a search for a new president would begin immediately, and he expects to have a candidate before Frohnmayer steps down in the summer of 2009.

In a letter to Pernsteiner and Gov. Ted Kulongoski, Frohnmayer said he intended to return to teaching and “other pursuits.” He is a tenured professor at the university’s law school and teaches an undergraduate seminar on leadership theories.

In an interview with The Associated Press on Tuesday morning, Frohnmayer said he was proud of the university’s ability to grow and thrive in many areas despite the sharp decline in state funding over the years. He said he would continue to lobby for more state support for higher education, and for the university to have more direct control over its own finances and revenues.

Asked to name a regret, he singled out his decision in 2000 to join an organization promoting worker rights in overseas factories, a move that angered Knight, though the rift was eventually healed.

Knight, who rarely speaks with the media, released a statement Tuesday calling Frohnmayer, “simply the best President the University of Oregon has ever had.”

Frohnmayer’s departure caps a season of churn for Oregon universities.

In the past five years, Oregon State, Southern Oregon University, and Western Oregon University have gotten new presidents. A presidential search is under way at Portland State University, and interim presidents are in place at Eastern Oregon University in La Grande and Oregon Institute of Technology in Klamath Falls.

Kulongoski called Frohnmayer “not only a great leader, but a great Oregonian,” and said he had been instrumental in helping a new generation of students see a future that included higher education.

Gordon Sayre, the president of the Faculty Senate and an associate professor of English, said Frohnmayer had provided “very good leadership for a decade and a half. We will be sorry to see him go.”

But faculty members do have concerns over the increasing prominence of athletics under Frohnmayer, Sayre said, especially since a large chunk of the $1 billion raised during his presidency has gone to athletics. Most recently, Frohnmayer helped win state approval for the most expensive athletics project in the school’s history, a $200 million new basketball arena.

Meanwhile, Sayre said, the administration has said it supports an increase in faculty salaries, but “we have not seen much progress.”

Frohnmayer points out that the athletics department gets no general fund dollars.

“Tens of millions of dollars that have come to the academic pursuits of the university are from people who have started by giving to the Duck Athletic Fund,” he said.

Emily McLain, the student body president, said students did not always agree with Frohnmayer, on issues ranging from ethnic diversity on campus — or the lack thereof — to the housing crunch as enrollment numbers have increased.

But, she said, Frohnmayer was always willing and open to listen to students’ concerns, and straightforward with them about plans.

“I think a lot of folks will remember the effort that he put into being involved outside of the presidency, by going out and being a part of the teaching world,” she said.