After nearly 20 years in office, President Derek Curtis Bok announced today he will resign his post in June, 1991.

Bok, 60, said he made the decision to step down last fall.

"I've always had a feeling for the last few years that 20 years more or less would be right," Bok said in an interview with The Crimson today. "With the possibility of a major fundraising drive, I thought it best to step aside and have there be some continuity [in leadership] for the fund drive."

Bok's resignation leaves the top two posts in the University empty and awaiting appointments. Dean of the Faculty A. Michael Spence announced last month that he is leaving the University to become dean of Stanford University's business school.

The administrative vacancies come at a time when Harvard is gearing up for a major fundraising campaign, expected to be higher education's largest ever. The drive, originally slated to start in the fall of 1991, may be delayed because of Bok's decision, fundraisers said.

Although there has been speculation in recent years that Bok would go into government or become the head of a philanthropic foundation upon leaving Harvard, he said today he has no employment plans as of yet.

"I haven't really pursued it," Bok said. "I though it would be inappropriate to talk about jobs as long as I hadn't announced my resignation." He added that Corporation members have urged him to accept a University professorship and remain at Harvard.

The last decade has seen sporadic speculation about Bok's plans to resign. Several educators said today that the length of the president's tenure and the rumors of his resignation had somewhat prepared them for the announcement.

"It's like a 90-year-old grandmother," quipped Associate Dean for Undergraduate Education David Pilbeam. "You expect her to die every year, but you're shocked when she actually does."

Administrators and professors today praised Bok's accomplishments as president, crediting him with leaving the University in a much more stable position--academically and financially--than it was when he was appointed in 1970 after serving as dean of the Law School.

Among his greatest achievements, they said, have been restoring stability after the tumultuous 1960s; creating the Kennedy School of Government; increasing Harvard's emphasis on undergraduate education and teaching; and critically examining various aspects of the University in his annual reports.

"He cared about every nook and cranny of Harvard," said Geyser University Professor Henry Rosovsky, part of the seven-member Corporation, Harvard's chief governing board. "I find it impossible to imagine Harvard without Derek Bok."

Throughout his tenure, Bok has faced criticism from some students and alumni for his refusal to completely divest Harvard's investments in South Africa-related firms.

Others have attacked him for making the University more corporate, pointing to his creation of the Medical Science Partners, which markets University research, and the endowment's involvement in controversial leveraged buyouts.

But administrators said that despite the criticisms Bok has been a consensus-maker who weathered the University through many storms.