Deutsche Bank could move parts of its business from the UK to Germany if a referendum ends the UK's membership of the European Union.
The group is the first bank to publicly state it is examining the potential impact of a Brexit by setting up a "working group", according to the Financial Times, although it is in the early stages and "no decisions have been made yet".
Prime Minister David Cameron promised a referendum by the end of 2017 if the Conservatives won by a majority, which was the case in the recent elections.
However, many businesses and key industry figures have urged the government to carry out the referendum as soon as possible to avoid a period of uncertainty.
Last week Britain's Bank of England Governor Mark Carney and foreign secretary Philip Hammond called for a "fast" referendum on Britain's place in the EU.
Carney said the government should move towards a referendum "with appropriate speed", warning uncertainty is causing problems for business.
Further reading: Should wealth managers and providers fear a Brexit?
