Ratings are tumbling in the second series of The Osbournes of the US, with audience figures falling by nearly half.

The show, which films the family life of Black Sabbath singer Ozzy Osbourne, his wife Sharon and children Jack and Kelly, has prompted claims that viewers are tiring of the show.

The new series began on MTV in November with 6.6 million viewers, but by 14 January it had 3.3m people watching and the most recent episode improved slightly to 3.8 million.

Sharon Osbourne is to get her own talk show

But MTV is not concerned with the falling numbers, and its programming chief, Brian Graden, said ratings were being maintained through a "premi�re and repeat basis".

"If you're in my shoes, you're not complaining," he said.

But Harry Keeshan, who works for New York-based ad-buying firm PHD, said the drop in ratings did not bode well.

"The people came in, they tried it and they just haven't gotten back on it. I don't think a lot of these people will return," he said.

The second series of The Osbournes is much darker than the first.

Kelly Osbourne launched a music career off the back of the show

Sharon Osbourne was diagnosed with colon cancer in between the series, and is shown receiving treatment for the disease.

MTV are planning a third series of the show, once this season's 10 episodes have ended.

The family recently made headlines for a string of expletive when they handed out awards at the American Music Awards in Los Angeles last week.

Sharon Osbourne has agreed to host a talk show on Telepictures which will be syndicated around the US.

The show is expected to begin in the autumn.