Next year will be one of the most difficult in the process of absorbing Credit Suisse into UBS Group AG due to the “sticky” costs involved before the two lenders are legally fused, UBS Chairman Colm Kelleher said.

“When you do an integration as massively complicated, the easy part of the initial job loss is when you get rid of headcount,” Kelleher said at the FT Global Banking Summit in London on Tuesday. The bank has “over-delivered” on the integration so far, he said.

The Swiss bank continues to make progress on a multi-year integration and restructuring of its former rival which it acquired in an emergency rescue in March. The integration comes with a raft of potential difficulties from closing out positions to managing the legal liabilities inherited from Credit Suisse.

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“We have to shut down all of Credit Suisse’s legal entities, transfer all of that data across before we can even get rid of those control-functions and the associated costs,” he said.

“In 2024 we are very focused on making sure that we merge the parent banks legally and effectively, decommission what was Credit Suisse AG, merge the big subsidiaries,” Kelleher said. “And that will then allow us to tackle the issue of cost.”

UBS stock will be “totally revalued” in five years’ time if the integration of Credit Suisse is handled successfully, Kelleher said.

The Zurich-based bank posted a net loss of $785 million for the three months to September, its first quarterly loss in almost six years, as costs to absorb Credit Suisse came in at $2 billion. At the same time the bank reported stronger-than-expected client inflows in its wealth-management business, boosted by the first signs of stabilization at Credit Suisse.

(Updates with further Kelleher comments)