Groom will have responsibility for the European edition, both in print and online.
He will be based in London and Brussels and will oversee 40 reporters and stringers in Europe's capitals and major financial centres.
Groom has been political editor since 1999, after three years as the paper's regional affairs editor. Prior to that he served on the FT's labour staff during the industrial unrest of the early 1980s.
He also worked as deputy editor and editor of Scotland on Sunday for a combined spell of nine years and was involved with the launch of the FT's European edition in 1979.
Since the FT launched its European edition, circulation has grown to 155,000 copies per day.