Witz also told analysts the company was "working through" negotiations to combine the satellite radio giant with the Liberty SiriusXM tracking stock group, but put no firm timeline on completing the proposed transaction beyond "early Q3." Liberty Media, led by president and CEO Greg Maffei and chairman John Malone, owns an 83 percent stake in SiriusXM and is looking to take full control of the satellite radio company to offer investors a more attractive value proposition.