Santander UK bank will split into a retail arm for personal and small business customers, and a corporate bank for institutional clients and its markets business, the source said.

Javier San Felix, global head of retail across the group, will move to London to become head of the ringfenced retail bank. Steve Pateman, head of UK banking, will run the corporate bank, effectively the non-ringfenced bank, the source said.

The structure will set the bank up to conform with the new UK rules requiring ring-fenced banks to be in place from 2019, the source said.

Santander UK will start implementing the new structure in September and expects full operation to be implemented from January 2018, the source said.

(Reporting by Jesus Aguado in Madrid)