The actor, whose roles also included voicing the lead in the Pixar film Up, passed away "peacefully" on Sunday morning, his family said.
"Words cannot express the sadness we feel. With a kiss on your head-Goodnight dad. We love you."
The character Lou Grant was first introduced as Mary Richards's boss on The Mary Tyler Moore Show in the 1970s.
Grant, the irascible editor of the of the fictional Los Angeles Tribune, then became a character in a show in his own right from 1977 to 1982.
