Columbia University trustees installed former Rice University president George M. Rupp as its 18th president in a ceremony attended by more than 2,500 yesterday morning.

Rupp replaces President Emeritus Michael I. Sovern, who announced his retirement last June after 13 years of presiding over the university.

In his inaugural address, Rupp pledged to maintain "the distinctive character of [Columbia's] lovingly complex, fractious, yet also unified community."

He offered support for the university's committment to diversity and need-blind admissions, as well as to its core curriculum.

Rupp also proposed fostering closer ties between Columbia and the surrounding community, as well as between the university's arts and sciences and professional faculties.

"We have the opportunity to develop programs that integrate undergraduate education with professional preparation," he said.

Rupp received a Ph.D in religion from Harvard in 1972 and served as professor and dean of the Divinity School from 1979 until 1985. He then served as president of Rice for eight years, during which the school doubled its endowment and nearly tripled its applications.

Sovern's announcement of his impending retirement prompted a six-month nationwide search for his successor, conducted by a search committee made up of students, faculty, administrators and trustees.

Sovern praised the presidential selection in a statement yesterday. "I have no doubt he will win the hearts of all in the Columbia community," he said.

Rupp was a contender in Harvard's recent presidential search.