LOS ANGELES (Reuters) - "America's Got Talent" judge Sharon Osbourne on Tuesday said on Twitter that she will be leaving the popular television talent show at the end of this coming season, a decision that took NBC executives by surprise.

Osbourne, wife of rocker Ozzy Osbourne, sent a tweet on her verified feed addressed to fellow judge Howard Stern saying "My darling @HowardStern, money is not the reason I'm not returning to @nbcagt," but did not divulge any further details.

Robert Greenblatt, entertainment chairman of NBC, told a group of TV critics in Beverly Hills on Tuesday, that the tweet caught the network off guard.

"I have nothing to say about Sharon Osbourne. We don't even know what is going on. It is probably much ado about nothing," said Greenblatt, when asked about Osbourne's Twitter posting.

Representatives for Osbourne did not respond to Reuters for comment.

"America's Got Talent" has contestants display a variety of talents with the hope of winning $1 million.

Osbourne, 59, replaced singer Brandy Norwood on the judging panel in 2007, alongside David Hasselhoff and Piers Morgan. She was later joined by comedian Howie Mandel and this season by "shock jock" Stern.

Osbourne is also one of the hosts on CBS daytime chat show "The Talk."