A view of the exterior of the Citibank corporate headquarters in New York, New York, U.S. May 20, 2015. REUTERS/Mike Segar/Files

FRANKFURT/LONDON (Reuters) - U.S. bank Citigroup Inc C.N is set to become the latest Wall Street bank to pick Frankfurt as its European Union base this week in preparation for when Britain leaves the European Union, two sources told Reuters on Monday.

Citi had earlier said it would choose Frankfurt to become its hub for sales and trading in the EU and move “a couple of hundred” jobs outside of London after Brexit. Citi’s European base move was reported on Monday by Sky News.

British finance minister Philip Hammond said this month that the country should push for a transitional deal to help businesses, as the government held its first high level meeting with corporate leaders to discuss Brexit.

Global banks have said they could move thousands of jobs out of Britain to prepare for the country’s planned EU exit.

Financial services firms need a regulated subsidiary in an EU country to offer products across the bloc, which could prompt some to move jobs out of Britain if it loses access to the European single market.

The Association of Foreign Banks in Germany expects 3,000 to 5,000 new jobs in Frankfurt over the next two years as a result of Brexit, its head Stefan Winter of UBS UBSG.S told German newspaper Welt am Sonntag in June.

Deutsche Bank AG DBKGn.DE, BNP Paribas SA BNPP.PA, Barclays Plc BARC.L and Bank of America Corp BAC.N are among the banks contemplating shifting some operations after Brexit.

Citi declined to comment.