John Cryan will resign for personal reasons as chief financial officer of UBS on May 31, the Swiss bank announced on Friday.

Tom Naratil will succeed Cryan, who will “pursue other interests outside of UBS,” the bank said in a statement. UBS also announced that its hired Sergio Ermotti as chairman and CEO of Europe, Middle East and Africa (EMEA) and member of the group executive board, effective April 1.

UBS' group chief executive Oswald Grübel praised Cryan, who became CFO amid the 2008 financial crisis.

“His knowledge and expertise were instrumental in the task of rebuilding UBS’s financial strength, winning him great respect both inside and outside of the firm,” Grübel said in a statement.

Since 2009, Naratil has been chief financial officer and chief risk officer of UBS’ wealth management Americas division. He will work closely with Cryan during the transition and will operate out of Zurich headquarters. Both executives are 49.

Naratil holds a master’s degree in economics from New York University and a bachelor’s degree in history from Yale University.

Ermotti, 50, is joining UBS from UniCredit where he was group deputy chief executive, responsible for the strategic business areas, corporate and investment banking and private banking. He joined UniCredit in December 2005 as head of markets and the investment banking division.

Ermotti graduated from the advanced management program at Oxford University.