Britney Spears is quite mean on `X Factor`: Simon Cowell

Los Angeles: Music mogul Simon Cowell says pop star Britney Spears is quite mean as a judge on the singing reality show.

Spears, 30, is in the judging panel along with Cowell, Demi Lovato and LA Reid, reported People magazine.

"I think the girls do a great job and the contestants are great. The show looks different than anything we`ve ever made before.

"Britney is a fascinating person because you just don`t know anything about her. She`s very unpredictable. You never know what is going to happen. She has taken this very seriously and she`s surprisingly quite mean," he said.

Cowell, 52, said he likes both Lovato and Spears and considers them two racehorses, who are very talented but very difficult to control.

"We have no control over these two whatsoever, and there are many, many times that we disagree. But that`s what`s made it more interesting this year. They are both unpredictable and have different and strong views," he added.

The show will premiere on September 12.