The agency, which has gross assets of £0.5m, will become part of Isobar in Asia Pacific and will be rebranded TUS Isobar.
The Upper Storey was founded in 2001 and has a client list including Microsoft, American Express, Intel, Daimler, Dell and Mediacorp.
TUS has three divisions, which include its main strategy and creative digital marketing division, as well as a motion graphics, 3D and design production division, Mofuro, and a production and technology hub, Studio TUS.
Last year, Aegis made more than 10 acquisitions, including MediaVest Manchester, Lithuanian media agency, Creative Media Services UAB, and Canadian social media moderation company, ICUC Moderation Services.
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