R+B superstar Beyonce Knowles has sparked reports she is planning a move to boyfriend SHAWN 'JAY-Z' CARTER's Def Jam label, so that he can help to "oversee" her career. The Irreplaceable singer is currently signed to Sony's Columbia imprint, but with her contract due to expire after her next two albums, Knowles is reportedly looking to make a move to Island Def Jam so she can team up with Carter in a professional capacity. An industry source tells PageSix, "(Carter) has been trying to get her to Def Jam for a while. He would love to oversee her career - he kind of does anyway." But the insider warns that Sony will not let Knowles go without a fight, adding, "Sony has had a bad year - all the hit acts, Justin Timberlake, Christina Aguilera and the 'American Idol' (US talent show) kids, are all on BMG. "They can't afford to lose Beyonce. They'll probably mortgage the farm to keep her. Which means a lot more money for Beyonce - and Jay-Z if they get married." Representatives for Sony, Knowles and Carter have yet to comment.