Mr Zhang is currently vice chairman of Citigroup's global banking division, and looks set to keep this role when he takes on his new responsibilities as chief operating officer of the Asia-Pacific corporate and investment banking unit in October.
He is set to move from his current base in New York to Hong Kong.
Industry observers have viewed the move as an attempt by Citigroup â one of the world's largest banks â to shore up its operations in Asia, where fast growing economies such as China represent new and exciting investment opportunities.
Citigroup today applied to raise its quota in Chinese securities investments in an attempt to strengthen its position in the emerging Chinese market.
Currently, the Chinese authorities allow the bank to invest up to $550 million in Chinese stocks as part of its Qualified Foreign Institutional Investor program.