Simon Cowell was keen to sign the 23-year-old star up for the eleventh series after she impressed him during her stint as a guest judge.
But despite a series of meetings with the music mogul and show bosses, Rita has turned down the offer so she can focus on her singing career.
A friend told The Mirror: “Rita was formally offered the X Factor job and was very flattered, but turned it down.
“She is out in LA at the moment, having meetings, making contacts and working hard in the studio.
“Rita is bringing out a new album this summer – so that’s her priority.
“She wants to focus purely on her music and not get distracted by other things.
"She also saw how Jessie J’s album struggled after she appeared as a coach on The Voice, and thinks the two could be connected.
“Rita thinks Jessie might have come across badly on TV. For now, Rita is staying away from reality TV and is concentrating on the day job.”
Rita has previously spoken about why 'X Factor' might not be for her.
“There were talks. But if I were to take on that role, it would have to be at a point when I could give it my full attention," she said.
“I have so much to accomplish first and it’s kind of a full-time job being on X Factor. It’s not like a nine to five. It’s constant, for months.”
It was hoped that Rita would complete a brand new line-up for the next series of 'X Factor' that will reportedly see the return of Cheryl Cole and Simon Cowell to the panel alongside Louis Walsh following the departure of Sharon Osbourne and Nicole Scherzinger.
Dannii Minogue was also rumoured to be making a comeback but has since denied she will be returning.
Last month the former judge said: “I don’t know who is on the panel but it won’t be me.”