UBS said its board of directors had given the green light for the respective parent banks, UBS AG and Credit Suisse AG, to fuse.

"The completion of the merger is subject to regulatory approvals and is expected to happen in 2024," UBS said in a statement.

It has previously said it expects to merge the parent banks, the respective Swiss businesses, as well as the U.S. intermediate holding companies in 2024.

The move will mean that Credit Suisse will no longer function as an independent bank and will allow for the first waves of client migration in its core businesses.

UBS's Chairman and CEO have both warned that the integration would not be a straightforward process and that from an operational perspective, 2024 will be a decisive year.

UBS CEO Sergio Ermotti said in November synergies were expected to be realised in 2025 and 2026.

(Reporting by Noele Illien, Editing by Rachel More, Elaine Hardcastle)