A week before Stern makes his debut on the NBC show, the Parents Television Council (PTC) said on Monday it had written to 91 companies who have previously run commercials or sponsored "America's Got Talent" asking them to place their ads elsewhere.

The PTC said Stern, a radio DJ with satellite broadcaster SiriusXM, has a reputation for "sleaze and misogyny" and a "decades-long penchant for profanity."

"The risk of associating your hard-earned corporate brand image with such 'shock' is not worth the cost involved - a cost not just in terms of wasted media dollars, but also in terms of countless millions of dollars in customer goodwill," PTC president Tim Winter wrote in the letter.

"I assure you that every advertiser on 'America's Got Talent' will be held publicly accountable for underwriting any of the inevitably vile antics of Howard Stern," Winter added.

Stern has built a reputation over decades as a radio show host, currently airing on the Sirius XM satellite network, who often uses foul language and discusses sexual content. During his career, he has taken his show to TV, wrote a book and even produced a movie, "Private Parts," loosely based on his life.

He was hired by "America's Got Talent" creator Simon Cowell and is expected to drive millions of new viewers to the family-friendly show - the most popular summer TV program on U.S. television - when it returns to U.S. airwaves on May 14.

So far Stern has appeared in several promotional clips, displaying a generally compassionate attitude to contestants mixed with only a few sharp quips.

NBC did not respond on Monday to calls for comment on the PTC letter.

(Reporting By Jill Serjeant; Editing by Bob Tourtellotte)

• A Permanent Economic Emergency