"The board unanimously determined that Andreas Berger is the right person to build on the firm's current momentum and lead Swiss Re into the next phase of its development," said Jacques de Vaucleroy, vice chairman of Swiss Re's board.

The sudden announcement follows a strong recovery by the firm in 2023 after a challenging 2022, which has helped to push the company's stock to its highest level in several years. Net profit at Swiss Re surged 580% in 2023.

A company spokesperson said Mumenthaler had had a long tenure, describing the handover as an "orderly transition."

"The company is in a good position, and markets are good. So it's a good time for a change," the spokesperson said.

De Vaucleroy said Berger had a convincing track record, underscored by the successful turnaround of the corporate solutions business unit he has led.

Rwanda-born Berger, 57, is a German national who joined Swiss Re in March 2019 as CEO of corporate solutions and member of the group executive committee, the company said.

The 54-year-old Mumenthaler, who will be leaving the company, joined Swiss Re in 1999 and rose through the ranks to become CEO in July 2016.

(Reporting by Andrey Sychev and Paul Arnold; Editing by Dave Graham and Jacqueline Wong)