News Corporation said on Friday that the deputy chief operating officer, Lachlan Murdoch, has resigned, a surprise move that is likely to fuel speculation over the leadership succession at one of the world’s largest and most high-profile print and broadcast companies.

[The Wall Street Journal reported on its Web site last night that Lachlan Murdoch’s exit is related to a rift between his father and the four older Murdoch children, three from Mr. Murdoch’s second wife Anna and one from his first marriage. The newspaper reports that Rupert Murdoch is seeking for his two youngest children, from his wife Wendi Deng, a share in block of voting stock worth $5.1 billion held in a family trust.]

Less than a year after News Corporations’s relocation to America, Lachlan Murdoch, the eldest son of the chairman and chief executive, Rupert Murdoch, said he will officially leave on August 31 and return to Australia. Lachlan Murdoch, 33, had been seen as the favorite to take the helm from his father, who has given no indication that he’ll retire.

“I am particularly saddened by my son’s decision and thank him for his terrific contribution to the company,” Rupert Murdoch said in a statement. Lachlan Murdoch will relinquish his executive roles, but will remain a director and advise the company in “a number of areas,” he said.

With Lachlan Murdoch’s departure, eyes are likely to turn to his younger brother and British Sky Broadcasting Group chief executive James Murdoch, 32, who has also been tipped as a successor to his father.

Analysts said Chief Operating Officer Peter Chernin, Rupert Murdoch’s right-hand man, is another contender for the CEO job in the short term, and he may assume Lachlan Murdoch’s responsibilities. Mr. Chernin, who takes home a larger salary than Rupert Murdoch, is well regarded by investors.

James Murdoch “should eventually take control, but not until Chernin decides to leave the company and/or the board deems him “ready,'” a Merrill Lynch analyst, Jessica Reif Cohen, said in a note to clients. She rates the stock buy with a $27 target price.

News Corporation wasn’t immediately available to comment on Lachlan Murdoch’s likely successor. A BSkyB spokesman declined to comment.

Succession has been a contentious issue with the 74-year-old Murdoch, whose family is the largest shareholder in News Corporation. In the past, Mr. Murdoch has said the only way the board and investors will get rid of him, will be in a box.

Lachlan Murdoch’s decision to quit his post in New York “solidifies” James Murdoch as the eventual successor, an analyst at UBS, Aryeh Bourkoff, said. News Corporation is UBS’s top pick in its sector, and the bank has a buy 2 rating and $23 target price.

James Murdoch took the helm of News Corporation’s U.K. broadcasting affiliate BSkyB in late 2003 amid strong criticism from institutional investors, who questioned his experience and ability to run a large company and were concerned that he would put News Corporation’s interests above those of other shareholders. Analysts don’t expect him to change jobs soon, given he’s been at BSkyB for less than two years.

With assets in America and around the globe including Hollywood film operations, newspapers, TV, book publishing, and satellite-TV delivery, News Corporation will need to find an executive with wide-ranging industry experience, as well as someone who can work with Rupert Murdoch. Mr. Murdoch is well known within the industry for being a tough task master, who keeps a close eye on the business, which was started with one newspaper bequeathed to him in the small city of Adelaide, Australia.

John Malone’s Liberty Media Corporation, which has an 18% voting stake in News Corporation, is likely to play a role in the selection of Lachlan Murdoch’s replacement as deputy COO. Liberty Media wasn’t immediately available for comment.

Relations between Mr. Malone and Rupert Murdoch were strained last year after Liberty Media amassed a larger stake in News Corporation. In response, News Corporation adopted a “poison-pill” takeover defense to block Liberty Media from raising its voting stake any further.

Lachlan Murdoch will remain a director. “I will remain on the board, and I am excited about my continued involvement with the company in a different role,” he said in a statement. “I look forward to returning home to Australia with my wife, Sarah, and son, Kalan, in the very near future.”

An Atlantic Equities analyst, Hamilton Faber, said he was told by News Corporation that Lachlan Murdoch’s commute between New York and Sydney, where his wife and son are based, was starting to take its toll, “so it was just a question of putting the family in front of the company.”

“That said, you kind of wonder whether it was becoming clear that he was not in the running to take over from his father,” Mr. Faber said.

Elisabeth Murdoch, the second-eldest of the six Murdoch children, quit the family business in similar circumstances. When she was 31, she quit her post as managing director of BSkyB in 2000 to spend more time with her family.