TSB has announced its boss will be leaving the bank to become chief executive of its Spanish owner.

Marc Armengol will step down to take up the new role at Sabadell.

The move is set to coincide with TSB being bought by its bigger rival Santander, which the firms expect to happen during the first half of this year.

Subject to the approval of regulators, it means Mr Armengol will take on the new job after May.

TSB said it will give an update on who will succeed him as chief executive closer to that time.

Mr Armengol rejoined TSB in March last year, having previously been a strategy director for the bank and a member of its board since 2022.

He had moved from his role as chief operating officer for Sabadell, which is the fourth largest bank in Spain and owner of TSB for more than a decade.

Santander struck a deal last year to buy the British bank from its parent firm Sabadell.

The deal valued TSB at £2.65 billion but the sale price is estimated to rise to £2.9 billion once the transaction completes.

Santander said acquiring TSB would help it be more profitable in the UK.

It plans to integrate the brand into its group, which raised concerns about the possibility for job cuts and branch closures across the combined group.

TSB chairman Nick Prettejohn said: “While Marc’s appointment is just reward for everything he has achieved personally, it is also testament to the role TSB has played in supporting Sabadell Group’s growth and success.

“Over the past five years, TSB has contributed significantly to the financial performance of Sabadell, and Marc has been at the heart of that transformation – first as TSB’s director of corporate strategy, then as a board director, and more recently as CEO.”

Mr Armengol will take over from Sabadell’s current chief executive Cesar Gonzalez-Bueno.