FILE PHOTO: 21st Century Fox Executive Co-Chairmen Rupert Murdoch (L) and his son Lachlan attend the first day of the annual Allen and Co. media conference in Sun Valley, Idaho July 8, 2015. REUTERS/Mike Blake

(Reuters) - Twenty First Century Fox's FOXA.O Chief Executive Officer James Murdoch will leave the company and be succeeded by brother Lachlan once the company sells off its TV and film assets to Walt Disney Co DIS.N.

James, younger son of the media tycoon Rupert Murdoch, decided months ago that he will pursue an opportunity of his own after quitting Fox, a source familiar with the matter told Reuters on Wednesday.

Lachlan and Rupert Murdoch will serve as co-chairmen of the new Fox, while current Chief Financial Officer John Nallen will also take the role of chief operating officer.

Fox agreed last year to sell the bulk of its film and TV assets to Walt Disney in a $52.4 billion deal. It expects to ask shareholders for approval of the transaction this summer.

The company has declined to comment on reports that Comcast Corp CMCSA.O is preparing a rival all-cash offer for the same Fox assets.

The new Fox will house assets including Fox News, Fox Business Network and sports cable networks, the company said.

James Murdoch currently serves as chairman of Sky PLC SKYB.L, where he was earlier forced out for four years after a phone-hacking scandal.