Erich Segal, a Yale classics professor who moonlighted as a screenwriter, had written a screenplay about two star-crossed lovers. His literary agent, Lois Wallace, thought it could also work as a novel and suggested that he turn it into one before the movie was made.
That novel, “Love Story,” spent more than a year on The New York Times’s best-seller list and has sold tens of millions of copies. The 1970 film, starring Ryan O’Neal and Ali MacGraw, grossed nearly $200 million and received seven Academy Award nominations.
Ms. Wallace, who later ran one of the most respected literary agencies in New York, died on April 4 in Manhattan. She was 73. The cause was complications of lung cancer, said Jeff Hoffman, an associate at the Wallace Literary Agency.
If her agency did not match the size of the big firms, it nevertheless gained prestige through its clients, among them William F. Buckley Jr., Joan Didion and Don DeLillo. Ms. Wallace helped Mr. DeLillo sell his novels “White Noise” and “Mao II.” She also helped Simon Winchester with his early work, though they parted ways before the publication of “The Professor and the Madman,” about an asylum inmate who was a prolific contributor of definitions to The Oxford English Dictionary.
Another client, the economist, writer and actor Ben Stein, recalled her tenacity in a memorial he wrote for The American Spectator. “She never conceded defeat on a book,” he wrote, “and she never conceded that anyone who owed me money should be allowed to get away with it.”
She was born Lois Kahn in Manhattan on May 25, 1940. She graduated from the Brearley School and Vassar College before she was hired as the celebrated editor Harvey Ginsberg’s secretary at G. P. Putnam Sons in 1961.
She married Tom Wallace, a book editor, in 1962. They divorced in 1999. She is survived by their son, George.
Ms. Wallace moved to the Harold Ober Literary Agency in 1963 and was hired by William Morris’s literature department in the late 1960s. She became co-director there before Mr. Segal’s breakthrough success allowed her to found her own agency with two partners in 1974.
Near the end of his article, Mr. Stein enumerated some of the qualities that he thought made Ms. Wallace such a successful advocate.
“She was not warm and cuddly,” he wrote. “She could be tough. But she was as loyal as the day is long. She had the elegance of a bygone era. She was fanatical in her determination to get things sold.”