Arnold Stang, an actor who appeared alongside Milton Berle and Frank Sinatra and was known for his nerdy looks and distinctive nasal voice, has died. He was 91.

Stang died Sunday of pneumonia at Newton-Wellesley Hospital in Massachusetts, said JoAnne Stang, his wife of 60 years.

She attributed her husband's career longevity to his willingness to tackle any professional challenge.

"He was really unique, because he could perform in any role, comedy or drama, he just loved it all," she said Tuesday. "He always thought of himself just as an actor, not any particular kind of actor, but just an actor who would play whatever he was asked to play."

Despite often playing goofy characters, Stang was the consummate professional, preparing the same for his biggest roles and the smallest commercials.

"I remember how smart he was, and how hardworking, and how disciplined he was, no matter what the role," his wife said.

The slight and diminutive Stang started his career on the radio as a teenager and never lost his love of the medium.

JoAnne Stang remembers her husband zipping across Manhattan in the 1940s and '50s, from radio show to radio show, all live and challenging in their own way because all the acting is done through voice, with no facial expressions or body language, she said.

"That was his education," she said.

He played alongside Berle on radio and television in the 1950s, starred as Sinatra's sidekick in the 1955 movie "The Man with the Golden Arm," and was a member of the ensemble comedic cast of "It's a Mad, Mad, Mad, Mad World" in 1963.

The dramatic role alongside Sinatra was one of his favorites, his wife said.

He voiced cartoons, including the lead character in the 1960s cartoon "Top Cat," and did dozens of commercials, perhaps most notably for the Chunky candy bar.

He appeared in movies alongside Arnold Schwarzenegger and Bill Cosby and continued acting into his 80s, playing a role in the 1993 movie "Dennis the Menace."

Stang invented and mischievously perpetuated a story that he was born and raised in the Boston suburb of Chelsea. But his wife said he was really raised in Brooklyn. He lived in the Boston suburb of Needham for the past decade.

Stang is also survived by son David and daughter Deborah.

Funeral services are private.