Britney Spears hasn't signed 'X Factor' deal. [Photo/Agencies]

Britney Spears has not signed on to be a judge on 'The X Factor' USA.

Sources connected with the 30-year-old singer told TMZ they are very close to signing a deal but are working out the last few details.

Britney reportedly expecting to be making $15 million as a panelist on the forthcoming season, however contracts have not be completed yet.

Now insiders say the mother-of-two should be signing up to the project headed by Simon Cowell in the next day or two.

Apparently the Fox network are planning to make the announcement on Monday at the Upfronts in New York City, where the autumn lineup is unveiled.

The agreement is almost certain to be signed but not by the twice married star, who is now engaged to manager Jason Trawick.

Since she is under a conservatorship, her father Jamie Spears and fiancé Jason - the co-conservators - will be the ones to sign on her behalf.

The contract must then be approved by the judge handling the conservatorship, however sources connected with Britney say it has already been pre-approved.