Bessent is forming Key Square Group with a $2 billion investment from Soros, according to a memo sent on Tuesday to employees of Soros Fund Management, where he serves as chief investment officer.

"Over the past four years, Scott has managed the firm's assets with skill and dedication," Robert Soros, George's son, said in the memo reviewed by Reuters. "He has decided to start his own venture because of the constraints involved in working with a family office structure, which prevent him from raising outside capital."

Bessent has spent much of his career managing money for Soros, overseeing his European investments for about eight years in the 1990s, and returning to the firm in late 2011.

"Scott will continue to advise SFM on an informal basis and remains close to George Soros and the Soros family," Robert Soros said in his memo. "Upon Scott's departure, the firm's investment strategy and asset allocation will be managed by the existing committees established by Scott and myself, which already play an active role in both processes."

(Reporting by Jennifer Ablan; Editing by Richard Chang)

By Jennifer Ablan