(contactmusic.com ) - Rap superstar 50 Cent has banned Ciara from collaborating with Birdman and Lil' Wayne following a dispute with their record label. The In Da Club hitmaker has asked R+B star Ciara not to record with artists at Cash Money Records following a feud between the label and G-Unit - 50 Cent's hip-hop group. According to MediaTakeOut.com, the rapper - real name Curtis Jackson - is fuming after G-Unit star Young Buck signed for Cash Money Records. And as revenge, Jackson has stopped a collaboration between Ciara and Cash Money Records founder Bryan 'Birdman' Williams. A source tells the website, "Nobody affiliated with 50 Cent can be affiliated with his enemy."