Britney Spears Credit: Jason Merritt/Getty

Britney Spears will always have the x factor -- but the X Factor no longer has Britney Spears. After months of speculation and mixed reviews for her performance as a judge on the second season of the FOX reality competition, the 31-year-old singer is leaving the series, two sources confirm to Us Weekly. (A rep for FOX had no comment.) On her 2013 agenda? Recording her eighth studio album with the likes of will.iam and other superstar producers, plus an accompanying tour.

But the "I Wanna Go" singer may have simply beaten X Factor producers to the punch. Us Weekly was first to report late last month that producers were planning to show Spears the door. "Britney will get the boot," an insider told Us of Spears, who joined the show in May, along with fellow newcomer Demi Lovato. "Producers wanted her for the long haul, but it isn't working."

Spears signed a whopping $15 million contract for one season -- and show runners were disappointed with the energy she brought to the show. "They paid all that for her to say 'amazing,' and offer half-claps," a second insider said. Co-creator Simon Cowell, a third source said "wanted crazy Britney, but he got boring Britney."

The popster joins the likes of Paula Abdul, Nicole Scherzinger and Cheryl Cole -- who all were fired after season one; judge L.A. Reid also recently announced his decision to leave earlier this month.

At a TCA panel in Pasadena, Calif. on Tuesday Jan. 8, FOX executive was diplomatic about Spears' run on the show.

Kevin Reilly addressed X Factor and how Britney Spears performed and if she will come back: "I thought it went very, very well... I think Britney did a really good job ... She tucked in really nicely on that bench. For next year, I don't know."