Deutsche Bank has set up a working group to investigate whether parts of its British divisions should be moved to Germany if the UK leaves the EU.
The company employs 9,000 people in the UK but says no decision has been made.
Prime Minister David Cameron has promised a referendum on the UK’s membership of the EU by the end of 2017.
Last month Deutsche Bank AG was fined £227m for Libor and Euribor-related misconduct.
Earlier this year, HSBC suggested it might move from London.
