Keller died on Monday of complications from Alzheimer's disease, his son Casey said.

A son of Polish immigrants, Keller moved from Chicago to New York in the early 1950s to pursue a career in comedy. He found success in 1955 when he joined the renowned writing staff that worked on Sid Caesar's television show, a spinoff of the popular programme Your Show of Shows.

Keller was the inspiration for the character Milton in the Broadway play Laughter on the 23rd Floor, based on Simon's time working on the shows, his son said.

He also wrote variety shows for such stars as Sinatra, Loren, Dick Van Dyke, Danny Kaye and Dinah Shore. He won an Emmy for a show he wrote for Carol Channing.

Keller also had a successful career as a composer and songwriter and performed in a jazz band with actors George Segal and Conrad Janis. -- AP