LOS ANGELES — Don LaFontaine, the man who popularized the now loved-catch phrase, "in a world where..." and lent his voice to thousands of movie previews, has died. He was 68.

LaFontaine died Monday at Cedars-Sinai Medical Center from complications in the treatment of an ongoing illness, said Vanessa Gilbert, his agent.

LaFontaine made more than 5,000 previews, called trailers, in his 33-year career while working for the top studios and television networks.

In a rare on-screen appearance in 2006, he parodied himself on a series of U.S. television commercials for a car insurance company where he played himself telling a customer, "In a world where both of our cars were totally under water..."

In an interview last year, LaFontaine explained the strategy behind the phrase.

"We have to very rapidly establish the world we are transporting them to," he said of his viewers. "That's very easily done by saying, 'In a world where ... violence rules.' 'In a world where ... men are slaves and women are the conquerors.' You very rapidly set the scene."

LaFontaine insisted he never cared that no one knew his name or his face, though everyone knew his voice.

LaFontaine went on to work in the promo industry in the early 1960s. As an audio engineer, he produced radio spots for movies with producer Floyd Peterson.

When an announcer didn't show up for a recording session in 1965, LaFontaine voiced his first narration, a promo for the film, "Gunfighters of Casa Grande." The client, Metro-Goldwyn-Mayer, liked his performance.

LaFontaine remained active until recently, averaging seven to 10 voiceover sessions a day. He worked from a home studio his wife nicknamed "The Hole," where his fax machine delivered scripts.

LaFontaine is survived by his wife, the singer and actress Nita Whitaker, and three daughters.

His funeral arrangements were pending.