Robbie Williams will appear on X Factor

London (ANI): Popstar Robbie Williams has agreed to make an appearance on The X Factor. The former Take That star's website confirmed that the 35-year-old will feature on the ITV1 show's sixth series, which kicks off on August 22, reports the Sun.

It read: "We're very excited to tell you that this is true! Details are still being finalised so make sure you stay tuned for further announcements."

Madonna, Rihanna, Whitney Houston and Lily Allen are other singers being lined up to take part.