The move comes ahead of The Sun and Fox television owner’s split into two companies. Miller, according to a statement from News Corporation chairman and CEO Rupert Murdoch, has decided to return to an “operational and entrepreneurial role with a standalone company”.
Miller joined News Corporation from AOL in 2009 as chief digital officer. He oversaw attempts to relaunch MySpace, rebranding and repositioning it as music platform in 2010 to differentiate it from Facebook.
It was sold, however, for a cut price $35m to Specific Media, a fraction of the $580m paid in 2005 when it was the leading social network.
Miller also oversaw News Corporation’s stake in online video site Hulu and led News Corp’s investment in Roku, which makes set-top boxes for video streaming.
He will remain as an adviser to News Corp until autumn 2013.
The media company is preparing to separate its publishing and entertainment business into two separately traded businnesses. Businesses such as News International, the Wall Street Journal and book publisher HarperCollins will operate separately from News Corp’s Fox television network and movie studio arm.