The British star is believed to have been snubbed by Fox bosses because she is not a household name in the US, and because of concerns over her heavy Georgie accent.
According to the Daily Star, Cheryl, 27, will serve as a mentor for Simon Cowell’s group during the later stages of the competition.
A source told the paper: 'Simon really wanted Cheryl on the panel with him but it’s been an unwinnable battle. People just don’t know who she is over there and people struggle to understand what she’s saying. Simon is consoling her with the offer of helping him win the first series, which would give her profile a massive boost. The fact is she’s got a decision to make. Simon Cowell is still one of her biggest supporters. But even though the X Factor is his idea, it's the executives at Fox who have the ultimate say over the make-up of the show.'