In an email sent Saturday, staff at The Times, The Sunday Times and The Sun were told that the 81-year-old Murdoch remained "fully committed" as chairman despite relinquishing his positions on a number of British boards, including News International, The Guardian reported Sunday.
The move was in line with plans to restructure his News Corporation empire, the message read.
Murdoch has already outlined plans to split the group into two, the daily said.
Under the proposals, US-based Fox TV and 20th Century Fox film studio will be separated from the publishing businesses, including The Wall Street Journal, alongside Murdoch's British and Australian newspapers and HarperCollins book publishing.
The media mogul plans to remain the chairman. Chase Carey, chief operating officer at News Corp, will be elevated to the No.2 spot at the entertainment business.
Murdoch has also resigned from the boards of a dozen companies with interests in the US, Australia and India, the daily said.
Staff were said to be concerned that the move was a precursor to putting the British units up for sale, following the shut down of the News of The World after the revelations of widespread phone hacking.
Earlier this year, a parliamentary committee said Murdoch was "not a fit person" to run an international business.