Barclays is planning to move its EU headquarters to Dublin, according to sources.
The bank is preparing for the relocation ahead of Brexit, Reuters reported.
"We have made clear repeatedly that we will plan for a range of Brexit contingencies, including building greater capacity into our existing operations in Dublin," a spokesman for Barclays said.
"Identifying available office space is a necessary and predictable part of that contingency planning process."
Barclays currently has a small operation in the Irish capital, employing around 100 people.
The news comes one week after Barclays boss Jes Staley said London will remain the "financial lungs of Europe" post-Brexit.
"I don't believe that the European finances system, our centre, will leave the City of London," he said.
The head of the French financial regulator said last month that many of the UK's major lenders were in talks about moving to Paris, after the chief of the British Bankers' Association said the banks were ready to leave London.
"Their hands are quivering over the relocation button," said the BBA's Anthony Browne.
"Many smaller banks plan to start relocating before Christmas. Bigger banks are expected to start in the first quarter of the year."