The new deal means that the label, which previously issued a ZTT boxed set, will take on responsibility for all physical releases, licensing and synchronisation for the ZTT recordings for the world excluding North America and Japan.
Union Square managing director Peter Stack says that the label has big plans for ZTT.
"We have some great re-issue ideas in planning, and we also look forward to implementing an active synchronisation strategy for film and TV licenses," he says. "We have worked with the SPZ Group [which owns ZTT] for many years via our successful exploitation of the Stiff Records catalogue, and we look forward to this new extension to our relationship."
The first releases under the new deal will be via USM's Salvo label in early 2010, with deluxe editions and boxed sets planned.
ZTT was home to artists including Art of Noise, Propaganda, Frankie Goes To Hollywood and 808 State.
It was formed by Trevor Horn, Jill Sinclair and Paul Morley in 1983 and enjoyed immediate success with Frankie Goes To Hollywood, whose first three singles all hit the UK Number One spot.
SPZ Group president Clive Black adds, "With several successful years of working together on Stiff Records under our belt, the SPZ Group is delighted to extend its working relationship with Union Square Music to include ZTT Records which remains one of the UK's seminal catalogues".