Derek C. Bok has named chemistry professor Jeremy R. Knowles to be the interim dean of the Faculty of Arts and Sciences, the University announced this afternoon.

Knowles, who served as dean of the Faculty from 1991 to 2002, will succeed current Faculty Dean William C. Kirby. Kirby announced his resignation in January under pressure from University President Lawrence H. Summers.

“This is certainly not an outcome that I ever expected,” Knowles said in a statement. “But I care deeply about the Faculty of Arts and Sciences and Harvard, and the opportunity to work with President Bok is compelling.”

The move means that next year, two of Harvard’s former leaders will reprise their roles at the helm of the University. Bok was president from 1971 to 1991.

“For me personally, it will be a distinct pleasure to work closely with someone who has been a good friend and colleague for more than 30 years," Bok said in a statement. "We are all in his debt for his willingness once again to accept the challenge of leading the Faculty of Arts and Sciences."

-Staff writer Javier C. Hernandez can be reached at jhernand@fas.harvard.edu.