Wyrley-Birch, who will retain his responsibilities as managing director of TRO UK, a post he was appointed to in December 2011, has been at the agency for 15 years.
The company said his appointment will allow it to focus on growing business across its global network following its expansion into Singapore and New Delhi.
As a result of his appointement, Wyrley-Birch's responsibilities extend to Frankfurt, Amsterdam and Paris.
TRO's clients include Google, which Wyrley-Birch has helped grow internationally, Diageo, BMW, Nissan and Nike.
Keith O'Loughlin, TRO's global chief executive, said: "TRO has enjoyed an impressive level of growth over the last five years, in difficult economic conditions and we are now ready to move to the next phase of our exciting journey.
"With Michael at the helm we will continue to deliver world-class, innovative campaigns and events for our global clients, while expanding into new countries and regions."
Wyrley-Birch added: "While the digital landscape and Google searches remove geographical barriers we've seen brands begin to restructure their marketing activities into regions rather than countries and TRO is responding to these client needs by extending its presence around the world."