Rupert Murdoch, the 84-year-old chief executive of Twenty-First Century Fox Inc, is preparing to step down and name his son James as successor at the entertainment conglomerate behind Fox News and the studio that makes "X-Men" movies, CNBC and Bloomberg reported on Thursday.

The elder Murdoch would stay on as chairman, according to CNBC. James Murdoch would work in tandem with his 43-year-old brother Lachlan in a "partnership," the CNBC report said, adding that Rupert would still have the final say in whatever goes on at Fox.

It was unclear whether the reorganization would take place this year or at the start of 2016, CNBC said.

The next Fox board meeting will discuss the matter of succession, the company said in a one-sentence statement.

The CNBC report said Chase Carey, president and chief operating officer of Twenty-First Century Fox, would stay on at the company in a yet-undefined advisory role.

"The most important thing in the immediate term is that Chase Carey not leave,a said Needham & Company Inc analyst Laura Martin. "Wall Street really cares about Chase Carey running this business. So if the implication of Rupert handing the title to his son is that Chase Carey leaves in the near term, we would expect that to negatively impact the stock prices."

Fox shares were down 0.50 percent at $32.79, while News Corp shares were off 0.23 percent at $14.61 in early trading.

As of April, the Murdochs owned 39 percent of voting shares in Fox and News Corp, the company that operates newspapers like The Wall Street Journal and book publisher HarperCollins, through a family trust. Fox split from News Corp in 2013.

A Harvard University dropout, James spent his early career as a cartoonist and co-founder of hip hop label Rawkus Records, which was bought by News Corp.

He joined News Corp in 1996, at the age of 23 and was soon installed as head of the company's Asian assets, including Star India. Four years later, he was named CEO of BSkyB, now known as Sky, that is 39 percent owned by Fox.

Some key investors have been warming to the idea that James has the ability to run Fox.

In interviews, some top investors who know James, and other people familiar with the company, describe him as curious and a risk taker like his father. But they also cite two big differences that they like: James is less sentimental about certain assets than his father and he is more enthusiastic about courting shareholders.

"James is a giant!" said Saudi Arabia's Prince Alwaleed bin Talal, a Murdoch family ally and one of Foxas top shareholders with a 6.6 percent voting stake, in a recent interview.