In an emotional letter on Monday announcing his retirement after more than 60 years at Yeshiva University, its chancellor, Norman Lamm, apologized for not responding more assertively when students at Yeshiva University High School for Boys said that two rabbis there had sexually abused them.

Dr. Lamm, who led the Modern Orthodox institution as president from 1976 to 2003 and has since served in the secondary role of chancellor, said his retirement afforded “a moment of reflection, gratitude, and appreciation.” He wrote that the timing of his departure had been set three years ago. But noting that the Bible encourages leaders to confess their shortcomings, he addressed the abuse, which students say took place during the late 1970s and early 1980s and came to light in articles in The Jewish Daily Forward beginning in December.

Dr. Lamm removed those alleged to have committed the abuse from their positions, but he did not contact legal authorities or notify their subsequent employers.

“At the time that inappropriate actions by individuals at Yeshiva were brought to my attention, I acted in a way that I thought was correct, but which now seems ill conceived,” Dr. Lamm wrote in the statement, which is posted on Yeshiva University’s Web site. “You submit to momentary compassion in according individuals the benefit of the doubt,” he added, “and in the process you lose the Promised Land. I recognize now that when we make decisions we risk, however inadvertently, the tragedy of receiving that calamitous report: tarof toraf Yosef, ‘Joseph is devoured,’ all our work is in vain, all we have put into our children has the risk of being undone because of a few well intentioned, but incorrect moves. And when that happens — one must do teshuvah,” the Hebrew word for repentance.