London ( CNN ) -- James Murdoch , the son of media magnate Rupert Murdoch , stepped down as the chairman of BSkyB on Tuesday , the British satellite broadcaster announced . He has been hammered by accusations that News Corp. 's British Sunday tabloid the News of the World systematically eavesdropped illegally on crime victims , politicians , celebrities and veterans in search of stories . Murdoch , 39 , has consistently denied knowing about the scale of phone hacking at the paper , which he ordered shut down last summer in the face of the scandal . He referred to it in his resignation , saying : `` I am determined that the interests of BSkyB should not be undermined by matters outside the scope of this company . '' He made clear he was trying to shield the satellite broadcaster from fallout from the newspaper scandal , saying : `` I believe that my resignation will help to ensure that there is no false conflation with events at a separate organization . '' Murdoch will stay on as a non-executive director of BSkyB . BSkyB shares in London fell about half a percentage point on the news of his resignation , and the Murdoch family 's News Corp. fell about the same at the open in New York . The resignation comes on the heels of his stepping down from News Corp. 's British newspaper publishing companies in the wake of scandals over the past year . When he quit as chairman of News International in February , the company said it was to focus on News Corp. 's pay television services . London 's Metropolitan Police are conducting three separate investigations into the scandal , which also includes allegations of e-mail hacking and police bribery . Dozens of people have been arrested but no one has been charged . Two parliamentary committees and an independent inquiry led by a judge are also probing the scandal . The scandal broke as News Corp. moved to expand its ownership of BSkyB last summer -- a plan it shelved as politicians and the public expressed outrage about the hacking of the voice mail of a missing teenage girl who later turned out to have been murdered . James Murdoch has been seen as a potential heir to his father 's media empire . He has twice been called to testify before lawmakers in London about what he knew of misconduct by staff at News International . In a letter to parliament 's Culture , Media and Sport committee last month , James Murdoch said he could have asked more questions of senior officers at the firm , but rejected the suggestion that his resignation as chief executive reflected unrevealed knowledge relating to the scandal . `` I take my share of responsibility for not uncovering wrongdoing earlier , '' he wrote in the letter , dated March 12 and published by lawmakers . A News Corp. board meeting is scheduled for later Tuesday . CNN 's Kendra Wates contributed to this report .
NEW : James Murdoch says he is quitting to shield BSkyB from a newspaper scandal . NEW : News Corp. and BSkyB shares both fall on the news . Murdoch has been hammered by scandal at the now-shuttered News of the World . Comment: