A huge shakeup is underway at Citi as 3 senior execs are stepping down - including CFO John Gerspach

Larry French/AP

• A shakeup is underway at the top levels of Citigroup, with three senior executives set to depart the firm.
• CFO John Gerspach is retiring next March, according to an internal memo from CEO Michael Corbat.
• Jim Cowles, the CEO of the bank's operations in Europe, the Middle East, and Africa, is leaving to start a nonprofit at the end of this year, and Bill Mills, the CEO of North American operations, will retire at the end of the year, according to the memo.
• Additionally, Corbat announced Kristine Braden, the bank's country officer for Switzerland, as his new chief of staff.

A major shakeup is underway at Citigroup as three top Citi execs are leaving the company, including CFO John Gerspach.

Gerspach, who joined Citi in 1990 and has been CFO for the past nine years, is retiring in March of next year, according to an internal memo from CEO Michael Corbat viewed by Business Insider.

Mark Mason, the CFO of the bank's Institutional Clients Group, will succeed Gerspach.

Additionally, Jim Cowles, the CEO of the bank's operations in Europe, the Middle East, and Africa, is leaving to start a nonprofit at the end of this year, and Bill Mills, the CEO of North American operations, will retire at the end of the year, according to the memo. They worked at Citi for 39 years and 36 years, respectively.

"Three members of our leadership team have made the difficult decision that it is time for them to leave Citi and begin the next stage of their lives," Corbat wrote in the memo. "They all worked incredibly hard to get our firm to where we are today-Citi is indisputably strong and stable, with a clear trajectory for continued growth."

Additionally, Kristine Braden, the bank's country officer for Switzerland, is replacing Sara Wechter as Corbat's chief of staff. Wechter was promoted to run human resources for the firm in April after Mike Murray stepped down.

This story is developing.