Media magnate Rupert Murdoch has stepped down from his board posts at companies that own several of his News Corporation's best-known newspapers, British media reports said.

Murdoch, 81, quit directorships at his British publishing subsidiary NI Group Ltd, NewsCorp Investments and Times Newspaper Holdings on Friday, the reports said.

In an e-mail sent to staff of The Times, The Sunday Times and The Sun on Saturday, News International’s chief executive Tom Mockridge said Murdoch had also stepped down from more than a dozen boards of companies with interests in the United States, Australia and India.

He said the resignations were part of the preparation for the planned split of News Corp into two firms, which media reports said is designed to separate the company’s newspaper and book publishing interests from its now dominant TV and film enterprises.

Murdoch is expected to chair both firms but to be chief executive only of the TV and film business, the BBC said.

The move has fueled rumors of a possible sell-off of Murdoch’s UK newspapers, despite Mockridge’s reassurances that the billionaire media mogul remains "fully committed" as chairman, reports said.

Murdoch's reputation has been badly damaged by a phone-hacking scandal at his now defunct UK newspaper News of The World. Earlier this year, a parliamentary committee said Murdoch was “not a fit person to exercise the stewardship of a major international company.”

The scandal prompted Murdoch’s son, James, to step down as chairman of News International in February.