James Murdoch quits GlaxoSmithKline board While he had replied to the email, he said he had not read it closely. There have also been calls for Mr Murdoch to give up the chair at BSkyB, which is 39pc owned by News Corp - though the majority of shareholders at the satellite broadcaster have remained supportive. Sir Christopher Gent, Glaxo chairman, said: "James has taken this decision to focus on his current duties as non-executive chairman of BSkyB, and following his decision to relocate to the United States" for News Corp. He thanked him for "the very strong contribution he has made." News Corp sources said Mr Murdoch's departure was "totally unrelated to the phone-hacking controversy. He has taken the decision because he is moving back to America and to focus on his current duties at News Corp and BSkyB," they said. Mr Murdoch is leaving as part of a shake-up of Glaxo's non-executives that will see long-standing directors quit at the 2013 AGM. Glaxo shares fell 20.5p to £14.20.