UBS’s Chief Executive sought to reassure Switzerland on Saturday over its new banking giant, created by the Swiss bank’s historic takeover of former rival Credit Suisse.

“The prospects for UBS are better than ever,” Sergio Ermotti wrote in an opinion piece published in the Swiss paper Tages-Anzeiger. “This also applies to the future of the Swiss financial centre and its important role in the Swiss economy.”

Ermotti, who returned to the bank as Chief Executive in a surprise move shortly after the government orchestrated rescue of Credit Suisse was announced, addressed public concern over the size of the combined bank.

He said “there is no doubt that UBS is a large bank,” but that the company’s business model also contributes to creating wealth for Switzerland.

With the official closing of the deal having taken place on Monday, details of how the two banks, with a combined balance sheet of $1.6 trillion and a workforce of 120,000, will be integrated remain sparse.

“The question of what will happen to Credit Suisse’s Swiss business also needs to be well thought through,” he said.