New York - News Corp chief Rupert Murdoch filed papers to divorce his third wife Wendi Deng on Thursday, citing an "irretrievably" broken marriage to a woman 38 years his junior.

The 82-year-old media tycoon's Chinese-born partner is perhaps best known for a 2011 incident when she leapt to defend her husband by striking a pie-wielding protester, prompting headlines calling her a "tiger wife."

"I can confirm for the record that Rupert filed in New York State Supreme Court this morning for divorce," his spokesman Steven Rubenstein told AFP.

"The line from the filing says 'the relationship between Mr Murdoch and Wendi has broken down irretrievably.'"

A source close to News Corp said the couple had a pre-nuptial agreement but did not elaborate.

The divorce will not affect the way in which the media empire is run as Deng does not have stock or voting rights in News Corp, the source said on condition of anonymity.

Murdoch's four oldest children, who are from previous marriages, have voting rights, the source said.

News of the impending divorce was not seen as a sign of problems at the company, and shares in News Corp rose 2.39 per cent Thursday to close at $31.68.

Deng, 44, married Murdoch in 1999 aboard a private yacht that he had reportedly bought for his retirement. They have two daughters, Grace and Chloe.

The news comes two days after News Corp shareholders approved a plan to split the Murdoch-led conglomerate into two independent firms on June 28.

The corporate split, described as a way to "unlock value" at the huge conglomerate, will create one company focusing on news and publishing another concentrating on television and film.

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Murdoch will remain in charge of both firms after the split, as chairman and chief executive of the entertainment-focused 21st Century Fox, and executive chairman of the new News Corporation, the publishing unit.

Deng met Murdoch while working at his Star Television company in Hong Kong, where former colleagues have described her as an expert networker with big ambitions.

Born in the eastern Chinese city of Xuzhou in 1968 - at the height of the Cultural Revolution - she left China at 19 to study in the United States. She graduated from the Yale School of Management in 1996.

Murdoch has spent a lifetime building his News Corp empire from a single Australian newspaper he inherited.

He moved to London where his purchase of the weekly News of the World in 1969 gave him a high profile foothold in the British market. He went on to buy The Sun, a daily which he turned into a popular and big-selling tabloid.

The success of his London-based newspapers helped finance his 1981 purchase of The Times and Sunday Times, both prestigious broadsheets, in an acquisition that met with intense opposition from parts of Britain's establishment.

He relocated to the United States where more bold acquisitions followed and where he became a naturalized US citizen in 1985.

The conglomerate made a string of high-profile acquisitions, including the Fox broadcast and Hollywood studios, and The Wall Street Journal.

His youngest son James, 40, is believed to be the heir apparent to the family empire.

James oversaw the closure of the 168-year-old News of The World tabloid, which folded on July 9 after the revelation the tabloid hacked into the phones of a murdered teenager and the families of dead soldiers.

James was named News Corp's deputy chief operating officer in March 2011 and serves as chief executive of the news and entertainment giant's international operations.

In 1998, Murdoch and his second wife, Anna, separated after 32 years of marriage. She then filed for divorce in California courts.

The three Murdoch children from his second marriage - Elizabeth, Lachlan and James - have worked for the company or served on the board of directors.

Murdoch previously was married to Patricia Booker, an Australian flight attendant, with whom he had one daughter.

Photos: AFP, Reuters, Youtube screengrabs

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