Mariah Carey is said to be in negotiations to become a judge on The US X Factor, shattering Cheryl Cole's dreams to build her profile in the US.
The 'Vision Of Love' singer is in talks to join the judging panel - ending months of speculation that Cheryl was a main contender for the role.
Mariah, 40, has told show bosses she will take the job if filming dates fit in with her work schedules.
Cowell was reported earlier this month of trying to persuade Fox TV executives that Cheryl was perfect for the show.
"Look, I've said I'd love Cheryl out there but whether it will happen, who knows?" the Mirror quoted him as saying last night.
"Mariah Carey would be an amazing addition to the US show. And she's exactly the right calibre of star that we want for the show.
"I can't say more because it's too early and I can't say. But there will be surprises," he said.
However, a source in the US reveals: "The Fox executives are totally against Cheryl joining the panel.
"Simon has put her forward and is trying to persuade them she's perfect for the job.
"But they're saying that together with her accent being difficult to understand, and nobody knowing who she is, she doesn't have the star qualities to draw in an audience.
"They are going to be competing with American Idol's star-studded panel of Aerosmith's Steven Tyler and J-Lo, and Cheryl just doesn't cut it compared to them. She's not a name.
"While Simon may want Cheryl he understands Fox's insistence that he delivers a strong panel to bring viewers, and therefore advertising, in and make as much money as they can," the source said.
The source adds: "Mariah Carey's people say she's fully behind the idea and they're very interested in taking talks further. Mariah has already had the initial meeting with Fox so she will more than likely take the spot Simon wanted for Cheryl."