Brossard, who will continue to hold the position of chairman of DDB France, will work with the regional presidents on the management and expansion of existing client relationships.
The management changes also see James Best, the global chief strategic officer, take on extra duties in the newly created global role of chief people officer.
Best said: "It's pretty evident that there's a need for this position in any organisation. My role will be to feed the hunger for growth and development. We've not had a global remit before because the agencies in such a young network have been very autonomous."
His enlarged remit will include developing, attracting and retaining talent, while growing an overarching worldwide human resources operation.
Until now DDB Worldwide has run human resources on a local agency level only.
Best also helped to establish the DDB University, the training and strategic education arm of the company.
Bray vacates the post of president of international brands. A successor is yet to be appointed. DDB Worldwide plans to look at internal and external candidates for the role, a position that entails responsibility for regional multinational accounts such as ExxonMobil and Johnson & Johnson.
"We will almost certainly look for an internal person, but there are a couple of other candidates and we need to think about it," Bray said.
"I would prefer an internal candidate because of existing clients and relationships within the network."
A replacement is expected to be announced in the New Year.