Simon Cowell is going to be leaving the TV reality show American Idol to launch the X Factor in the US.

As they say if it ain’t broke then don’t try and fix it , and the X Factor has proved to be a big success for Cowell in the UK so there is no reason to think that it will not be as big in the US.

Cowell has said that the X Factor show will join TV station Fox’ s line up next year and he will be on it.

Cowell’s decision to leave will be the biggest test to American Idol which is America’s most popular TV programme.

But Cowell has long been seen as the big star of the show thanks to his cutting commentary.

Cowell has said that it would be too difficult for him to do both shows .

Cowell and top Fox executives made the announcement in California, at a meeting of the Television Critics Association, saying they had reached an agreement only a few hours before.

Cowell said: “I was offered a lot of money to stay on. But that wasn’t the reason behind it. I wanted to do something different. I wanted a new challenge.”

Peter Price ,who is chairman of Fox, would not comment on possible replacements for Cowell. “We have to take our time on that,” he said

“We have to make sure the chemistry of the judges is as good as it can be,”

Cowell said he did not want to leave American Idol at a time when it was flagging in the ratings. “You want to leave on a high,” he said. “I’m very proud of what the show has achieved.”