Twitter Inc has appointed Katie Stanton its new media chief, placing the former Google executive at the heart of its crucial relationships with Hollywood and the global media industry, a source with knowledge of the move said on Monday. Stanton, formerly head of international strategy, fills in for Chloe Sladden, who left the online messaging service as part of a recent management shake-up that also included the departure of former chief operating officer Ali Rowghani. Twitter has reported lackluster user and usage growth for the last couple of quarters, and its stock price has nearly halved in the last six months. Stanton will now oversee Twitters continuing efforts to court TV networks, Hollywood studios and other media companies around the world.