NEW YORK Robert James Waller, author of the best-selling romantic novel "The Bridges of Madison County," has died at the age of 77, his literary agency said on Friday.
Waller died at his Texas home early on Friday morning, said Matt Belford of the Aaron M. Priest Literary Agency in New York. The cause of his death was not known.
Waller's 1992 novel about a brief, bitter-sweet love affair between an Iowa housewife and a photographer was turned into a 1995 movie starring Meryl Streep and Clint Eastwood, and a 2014 Broadway musical.
"The Bridges of Madison County" was translated into 40 languages and sold some 50 million copies.
Waller, an Iowa-born musician and photographer as well as a writer, authored six other novels. He also taught courses in management, mathematics and economics at the University of Northern Iowa for many years.
(Reporting by Jill Serjeant; Editing by Andrew Hay)