Rupert Murdoch’s long-held plan to hand over his media empire to his sons is now being realized.

Mr. Murdoch is expected to name his son James to succeed him as chief executive of 21st Century Fox, the sprawling entertainment company that includes cable and broadcast television networks, film studios and satellite companies, multiple people briefed on the plans said on Thursday.

He also is expected to elevate his son Lachlan to the role of co-executive chairman of the company. Lachlan, 43, is moving from Australia to Los Angeles and will work in partnership with James, 42, these people said.

Rupert, 84, will remain at the company as executive chairman.

The exact timing for the changes is unclear. They are said to be part of Rupert’s long-term succession plans and are likely to be discussed at a board meeting next week, two people said.

While his sons are stepping into the spotlight, Rupert is expected to continue to provide broad strategic oversight and will retain ultimate control of the company, said the two people. The family effectively controls both 21st Century Fox and News Corporation, the other half of the Murdoch media empire, through its ownership of almost 40 percent of the voting shares in both companies. Rupert Murdoch has more rights in the family trust than his children.