James Murdoch, the younger son of media mogul Rupert Murdoch, has resigned from the board of News Corporation citing "disagreements over editorial content".
In a filing to US regulators, he said he also disagreed with some "strategic decisions" made by the company.
The exact nature of the disagreements was not detailed.
But Mr Murdoch has previously criticised News Corp outlets, which include the Wall Street Journal, for climate change coverage.
In recent years James Murdoch has also found himself at odds - politically - with his father, BBC North America correspondent David Willis says.
Whilst Murdoch Senior has pledged support for Donald Trump, James Murdoch has reportedly contributed hundreds of thousands of dollars to the campaign of Mr Trump's Democratic rival, Joe Biden.
James Murdoch's departure from News Corp would, our correspondent says, appear to grant even more influence to his brother Lachlan who is generally thought to share his father's more conservative views.
Rupert, News Corp's executive chairman, and Lachlan, co-chairman, wished James well in a joint statement.
"We're grateful to James for his many years of service to the company," the statement said. "We wish him the very best in his future endeavours."
News Corp also owns The Times, The Sun and The Sunday Times in the UK, as well as a stable of Australian newspapers, including The Australian, The Daily Telegraph and The Herald Sun.
BDST: 1305 HRS, AUG 01, 2020