UBS Group announced that Sergio Ermotti is returning to the Swiss bank as chief executive officer to oversee the complicated acquisition of Credit Suisse Group.

Ermotti, 62, who is chairman of Swiss Re, returns on April 5 to a role he held for nine years from 2011 to 2020.

UBS said Ermotti “successfully repositioned UBS following the severe challenges arising from the global financial crisis.”

Ermotti replaces Ralph Hamers after just over two years in charge.

UBS said Hamers “has agreed to step down to serve the interests of the new combination, the Swiss financial sector and the country.”

On March 19, UBS agreed to take over Credit Suisse in a $3.25 billion rescue deal arranged by Swiss authorities.

The deal was backed by more than $217 billion of state cash and guarantees arranged by the Swiss government, central bank and regulators.

UBS said Hamers will remain at UBS and work alongside Ermotti as an advisor during a transition period to ensure a successful closure of the transaction and a smooth hand-over.

It said the UBS board took the decision “in light of the new challenges and priorities facing UBS after the announcement of the acquisition.”

Ermotti’s immediate challenges will probably include laying off thousands of staff and cutting back Credit Suisse’s investment bank operations.

UBS said of Ermotti: “In particular, he built financial strength and improved resilience by putting the firm’s leading global wealth and asset management business, and Swiss universal bank, at its core.

“He swiftly transformed the investment bank by cutting its footprint and achieved a profound culture change within the bank which allowed it to regain the trust of clients and other stakeholders, while restoring people’s pride in working for UBS.

“This unique experience, together with his deep understanding of the financial services industry in Switzerland and globally, make Sergio P. Ermotti ideally placed to pursue the integration of Credit Suisse.”

UBS chairman Colm Kelleher said: “Ralph has been an outstanding CEO of UBS, driving the group to unprecedented success despite a challenging environment.

“Under his leadership UBS built the strengths that have put us in a position to stabilize Credit Suisse and ensure a successful integration.

“On behalf of the whole board, I would like to express my deep respect and gratitude for all that Ralph has achieved over the last two-and-a-half years and for his instrumental role in delivering the Credit Suisse deal, as well as his understanding of the current situation and willingness to step down.

“While the acquisition will support UBS’s existing strategy, it imposes new priorities on us. With his unique experience, I am very confident that Sergio will deliver the successful integration that is so essential for both banks’ clients, employees and investors, and for Switzerland.

“I know Sergio will hit the ground running.”

Hamers said: “Integrating Credit Suisse is UBS’s single most important task and I am confident that Sergio will successfully guide the bank through this next phase.

“I am of course sorry to leave UBS, but circumstances have changed in ways that none of us expected. I am stepping aside in the interests of the new combined entity and its stakeholders, including Switzerland and its financial sector – it has been a pleasure and privilege to lead this great bank to where it is today.

“I would like to thank Colm and the board for their support and guidance, and I wish Sergio every success. I will support him during a transition period and I know he will lead UBS very effectively in the interests of all.”

Ermotti said: “I am honored to be asked to lead this bank at a time that is so important for all its stakeholders and for Switzerland.

“I would like to express my gratitude to Ralph for steering UBS so successfully.

“The task at hand is an urgent and challenging one. In order to do it in a sustainable and successful way, and in the interest of all stakeholders involved, we need to thoughtfully and systematically assess all options.

“I am conscious of the uncertainty many feel and I promise that, together with my colleagues, our full attention will be on delivering the best possible outcome for our clients, our employees, our shareholders and the Swiss government.”