Young will report to the executive creative director, Steve Henry, whom he worked with at HHCL, and look at new revenue streams for TBWA\ outside of traditional advertising arenas.
He joins a month after Tony McTear, the TBWA\ joint creative director, quit. McTear will not be replaced. Danny Brooke-Taylor, the other creative director, stays in place.
As well as McTear, TBWA\ has lost several members of its senior staff in recent months. At the end of June, it emerged that Victoria Davies, its managing director, and head of account management, Suzie Shaw, had both resigned.
The roles of Tracie Stokes, its head of TV, and Dick Butler, its vice-chairman, are also now understood to be under review. TBWA\London declined to comment.