Actress Suzanne Pleshette, best known as the feisty but level-headed wife of Bob Newhart on television's 1970's hit The Bob Newhart Show, has died at age of 70, say friends.

Pleshette died of respiratory failure at her Los Angeles home on Saturday, friends and associates told local media.

She had received chemotherapy for lung cancer in 2006 and appeared at a "Bob Newhart" reunion in September in a wheelchair.

Newhart issued a statement calling his co-star "an indomitable spirit" and "one of those people you thought would go on forever.

"She was a pro's pro and I know she was looking forward to getting a star on the Hollywood Walk of Fame on her birthday, January 31," said Newhart.

The raven-haired Pleshette, trained for the stage in New York, became a regular on television shows in the 1970s and 1980s and most recently appeared in a recurring role on NBC's Will & Grace.

But she was best loved as the no-nonsense Emily Hartley, foil to the wry Bob Newhart, on The Bob Newhart Show from 1972 to 1978.

With her saucy wit, throaty voice and flair for comedy, Pleshette was the antithesis of the traditional staid American television wife and the on-screen dynamic between the two leads guaranteed the show legions of fans.

The actress garnered two Emmy Award nominations for her work on the Newhart show as well as a nod for her leading performance in the 1991 television movie Leona Helmsley: The Queen of Mean.

Pleshette was married three times, most recently to comic actor Tom Poston, who appeared in the original Newhart series and returned to play handyman George Utley on the 1980s revival sitcom Newhart. Poston died in April 2007.