Citigroup Inc.’s longtime CFO John Gerspach will retire in March, to be replaced by Mark Mason, CFO of the institutional clients group, the third-largest U.S. bank told employees on Tuesday.

Gerspach, an accountant, joined Citigroup in 1990 and became CFO in July 2009. He became known for fielding analyst questions about the company’s irregular progress in divesting businesses, satisfying new capital rules imposed by regulators and failing to meet financial targets.

He also had to answer for problems that cropped up at far-flung operations around the world, including losing $500 million on fraudulent loans in its Mexican bank.

“He has represented our company exceptionally well, not just in good times but in tough ones as well,” CEO Mike Corbat said in the memo seen by Reuters.

Corbat also announced that North America CEO Bill Mills and Europe, Middle East and Africa CEO Jim Cowles would be leaving the bank at year-end, and named Kristine Braden, who is country officer for Switzerland, as his new chief of staff.

The changes follow an executive shuffle a few weeks ago at Citigroup’s consumer bank, which has had trouble keeping up with performance expectations on Wall Street.

Mason takes over the CFO role at a time of investor frustration with Citigroup’s lagging stock price. Its shares trade for about 1.2 times tangible book value compared with 2.1 times for shares of JPMorgan Chase & Co., the largest U.S. bank by assets.