Last week, the proposed acquisition of 21st Century Fox by The Walt Disney Company took a hit, much to fan dismay, when rival contender Comcast tabled a substantial, all-cash bid for the rights to intellectual properties owned by the Rupert Murdoch-founded company.
James Murdoch, Lachlan's 45-year-old brother, now helms Fox. Rupert Murdoch will remain joint chairman.
Lachlan's brother James - now Fox's chief executive officer - wasn't mentioned in Wednesday's statement.
"We have worked through the winter "standing up" a reimagined independent Fox", Lachlan Murdoch said in the statement.
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.
The company is yet to comment publicly on his future but sources close to him told Reuters on Wednesday that he had made up his mind months ago.
The new Fox will house assets including Fox News, Fox Business Network and sports cable networks, the company said.
"The new Fox will begin as the only media company exclusively focused on the domestic market; focused on what Americans love best - sports, news and entertainment, built and delivered for a US audience", said Rupert Murdoch, 87, on Wednesday. In this role, he works directly with the company's senior management and board of directors in developing global strategies and setting the overall corporate vision.
"It really is at the moment-and maybe it's an illusion, and maybe I'm naïve-but it's business as usual at Fox".
The executive will assume both the CEO and chairman jobs at the company, which is being referred to as New Fox.