University President Lawrence H. Summers said yesterday that he will marry his longtime partner, Professor of English Elisa New.

The couple was engaged over the weekend, Summers said. They will wed at a small ceremony with friends and family later this fall, according to Summers’ spokesman, John Longbrake.

New, who has dated the president for roughly four years, sported an engagement ring on campus yesterday.

Summers said last night that he was first introduced to New in 2001, shortly after arriving at Harvard, by economist Kenneth S. Rogoff, the Cabot professor of public policy, and his wife, Natasha Lance Rogoff.

New is an expert on American poetry, and her research interests range from Puritanism in colonial New England to modern Jewish literature.

“All of her work is very, very acutely sensitive to aesthetic issues,” Shakespeare scholar Stephen J. Greenblatt, the Cogan University professor at Harvard, said yesterday. “She’s a marvelous close reader of poetry. There are many qualities one would associate Larry Summers with, but an acute aesthetic sensitivity is not the first one that would come to mind.”

“In terms of the happy conjunction of personalities that represent different interests and engagements, it’s a very nice one,” Greenblatt said of the marriage.

As Summers faced a storm of criticism following his remarks on women in science early this year, New stood by his side—literally. She accompanied her embattled boyfriend as he exited two contentious faculty meetings in February.

The bride and bridegroom, both Jewish, each have three children from previous marriages.

Summers’ twin daughters, Pamela and Ruth, are 15. His son, Harry, is 12. New has three daughters, Yael, 19, Orli, 14, and Maya, 9.

Summers and his first wife, lawyer Victoria Perry, married in September 1984. She now lives in Bethesda, Md.

Summers is the first bachelor to occupy the president’s office at Harvard since John Thornton Kirkland, Class of 1789, according to “Harvard Rules,” a critique of Summers’ presidency by journalist Richard Bradley.

Before becoming Harvard’s 27th president in 2001, Summers served as chief economist of the World Bank and Treasury secretary.

Early in Summers’ tenure as president, tabloids were abuzz with rumors of his relationship with conservative radio host Laura Ingraham. But the romance did not last.

Summers’ relationship with New came under scrutiny after the English Department cancelled a controversial November 2002 lecture that was slated to be given by Irish poet Tom Paulin.