Shares of Internet radio pioneer Pandora Media Inc. shot up on Thursday after the company said CEO Joseph Kennedy is stepping down and it reported a narrower loss and higher revenue in the fourth quarter than analysts expected. Revenue from mobile ads also grew faster than listening on mobile devices, easing a key investor concern about the company's ability to make a profit from the booming segment. Shares jumped $2.42, or 20.6 percent, to $14.15 in after-hours trading. The last time Pandora hit $14 was Jan. 27, 2012. Kennedy, 53, has led the company as chairman and CEO since July 2004, will step down after a successor is found. "As part of our board discussions of the road that lies ahead, I reached the conclusion and advised the board that the time is right to begin a process to identify my successor," Kennedy said in a statement.