Coca-Cola did not deny the brief had been issued, but stated: "While we are very excited about the success of Coca-Cola Zero, we never comment on future marketing initiatives."
Agencies have two weeks to prepare presentations, and are expected to be made at Coca-Cola's regional headquarters in Hong Kong.
Coke Zero is Coca-Cola's sugar free brand targeted at men who avoid Coke Light because of its associated stigmas - such as being the beverage of choice for dieting women.