BI's group client services director Mike Davies has been promoted to BI Worldwide chief operating officer.
The restructure follows BI's acquisition of the remaining shares in the Mint Organization - based in Singapore, Shanghai and Dubai - earlier this year. It aims to develop BI's business in the UK and overseas.
A BI spokeswoman said: "Neither BI nor Mint are making any redundancies at present."
Bandell is relocating to Shanghai to develop BI's business in China and will continue to have responsibility for the agency's business outside the US.
The agency is making "significant capital investments" in new products designed to help bolster its UK business.
"These changes streamline our senior management team, making us more effective and efficient, and will enable us to leverage the experience and skills of individuals to the greatest effect," said Bandell.