The blue chip company caused an uproar in France when it decided in 2013 to move the 70-strong department from its Paris headquarters to London.

"We have just decided to bring it back to Paris. There is Brexit at play ... and then there is a question of costs," Pouyanne told a Euronext conference, answering questions about the attractiveness of Paris as a destination for business.

Companies are making final preparations as Britain is poised to officially leave the European Union on Jan. 31.

(Reporting by Maya Nikolaeva; Writing by Bate Felix; Editing by Louise Heavens)