Passporting allows for any financial firm to serve the whole EU region from a single base, cutting costs and red tape.

"As the future of passporting is uncertain post-Brexit, FCE is conducting a detailed study with a view to potentially applying for a banking license in Germany in addition to the license we currently hold in the U.K.," an FCE spokeswoman said.

(Reporting by Costas Pitas; Editing by Ruth Pitchford)