UBS Group AG completed the deal to acquire former rival Credit Suisse Group AG, sealing the biggest merger in banking since the 2008 financial crisis and creating a global wealth-management titan.

The Swiss bank announced the closing of the deal in an open letter in local and international newspapers on Monday. The takeover of Credit Suisse ends the lender’s 167-year independent existence.

The announcement caps more than two months of uncertainty for employees after UBS finalized negotiations with the Swiss government over a 9 billion Swiss franc ($10 billion) guarantee against potential losses on Credit Suisse assets. The deal sets UBS up for a windfall gain in the tens of billions of dollars and begins a period of complex integration likely to involve thousands of job cuts.

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UBS agreed to take over Credit Suisse in March in an emergency sale brokered by the government, after a confidence crisis and a torrent of client outflows sent it hurtling toward bankruptcy. At the helm of the combined bank, UBS Chief Executive Officer Sergio Ermotti now faces the task of fusing two highly overlapping companies and deciding which activities to jettison.