After eight years at the head of the largest public university system in the world, University of California President Richard C. Atkinson is stepping down.

Atkinson, 73, told the UC’s governing Board of Regents on Wednesday that he will be retiring next October after eight years on the job – three years more than he initially planned – saying it is time “for my grandchildren to see more of their grandfather.”

“These have been extremely rewarding years – challenging, stimulating and deeply interesting years – but the time has come to bring them to a close,” he said.

Regents showed their support with a standing ovation.

“Dick has done a magnificent job for this University,” said regents chairman John J. Moores, who called the announcement “a moment of considerable sadness.”

Atkinson was named president in August 1995, a month after UC Regents adopted SP-1, which eliminated the consideration of race and gender in admissions. The decision to end Affirmative Action drew fierce opposition from civil rights leaders and students. Like the eight other chancellors serving in 1995, Atkinson had opposed dropping Affirmative Action.

He lobbied for a number of changes to maintain diversity in admissions, including the “comprehensive review” system that looks at students’ socio-economic backgrounds as well as their academic performance.

In February 2001, Atkinson asked faculty to look into dropping the S.A.T., saying it was taking up too much of students’ time and money, and noting it had been criticized as unfair to minorities.

With about 170,000 students, the UC is the S.A.T.’s biggest customer. After some initial reluctance, officials at the College Board, which owns the S.A.T., agreed to revise the exam. The changes, which are expected to be introduced in March 2005, include adding an essay, dropping the analogy questions and making the math more advanced. The other major college exam, the A.C.T., also added an essay.

During Atkinson’s tenure, the UC’s enrollment has increased by 30,000 students, and the University has broken ground on a10th UC, located in Merced.

Atkinson has also handled a number of crises during his tenure, including a failed hospital merger with Stanford University and some high-profile troubles at the nuclear weapons labs UC manages for the Energy Dept. After Congress threatened to remove the UC as the manager, Atkinson restructured the lab management; a month ago a government review gave the labs the highest performance ratings possible in all categories.

Atkinson also dealt with serious budget constraints during his first year as president, but said Wednesday that the University has “recovered and thrived,” since then.

“Over the next 10 months, I will work to keep the University’s budget on as firm a footing as possible and to provide a smooth transition for my successor as president,” Atkinson said. “But for the long term, this University’s success lies in the capable hands of our creative, energetic and dedicated community of people.”

The entire University will miss Atkinson’s “visionary leadership,” UCSB Chancellor Henry Yang said.

“When he leaves the presidency in 10 months, he will leave behind a tremendous legacy – a UC system that … is stronger than ever, and that is determined to find the best and most equitable ways to attract and admit the outstanding students of this state,” Yang said.

Yang also cited Atkinson as an “outstanding educator,” and a “great friend to the Santa Barbara campus.”

“His work as UC president has been a model of wisdom and insight, and his extraordinary and distinguished career in the UC system will long serve as an inspiration to me and to all his UC colleagues,” Yang said.

Before taking over as UC president, Atkinson, a cognitive scientist, was chancellor of UC San Diego for 15 years. Before that, he directed the National Science Foundation in Washington, D.C. He has also worked at Stanford University and spent three years as a professor at UCLA.

The job of UC president is a $361,000-a-year position that entails overseeing a $17 billion enterprise – bigger than most Fortune 500 companies. The system includes nine campuses – a 10th is planned – five medical schools, three law schools and three national laboratories. The regents will appoint a search committee to find a new candidate for the job.

“I have been honored to serve as your president, and I owe many people a debt of gratitude,” Atkinson told the regents. “Most of all, I want to thank you for the opportunity to serve this great University and the people of California.”

-The Associated Press also contributed to this story.