Britney Spears -- J Lo Gets Her Crumbs in New Vegas Deal

Britney Spears is now the reigning queen of Vegas, and she's already flexed her royal muscles in J Lo's face.

Britney just signed a 2-year extension on her Vegas residency at Planet Hollywood. J Lo will also be performing at the same venue beginning in January. Sources familiar with Britney's new deal tell us, the venue gave Britney first pick at concert dates and Lopez got to choose from what was left.

As for the new deal ... it's sweet. We're told Britney will make an additional $5 million for the extension. She is currently under a $30 million/2 year deal, but the new one will pay her $35 mil.

She'll also be doing fewer performances so she's making more per show.

Our sources says the new deal, with merchandising, could top Celine Dion.