Jon Matthews, director of HKR Architects in Manchester, has left to set up the firm's Dubai office.
Phil Doyle remains as director in the Manchester office, which also recently saw the departure of another director, Nigel Jacques, to Sheppard Robson.
Matthews helped establish the King Street base for the group in 2006 along with Doyle.
HKR's regional work includes the Hive for Argent in Manchester's Northern Quarter, plans for the Brown Bros site for Artisan in Salford and the first phase of the Boddingtons brewery redevelopment for Ask Developments and Realty Estates.
No one was immediately available for comment.