KGO was the No. 1 rated station in the Bay Area for almost 30 years until 2010.
Executives say a shrinking audience led to the change.
"We thought that there would be a better opportunity to build audience by going to a semi-all news format," KGO News and Program Director Paul Hosley said. "Our talk format has been wonderful over the years for KGO, but the audience really hasn't stayed with us. The audience isn't there. We believe that news will attract more listeners."
KGO Radio is owned by Cumulus Media.
The Ronn Owens Show will remain on the air, as will current weekend programs.