It is believed that the pitch took place in February, and the business was handed to Saatchi & Saatchi in May on an annual retainer basis.
A new campaign is tipped to be launching in September, with preparations underway now.
The agency already handles other Mondelez China brands including Stride gum and four biscuit products (Prince, Ritz, U-Guan, Pacific).
The company claims that Cadbury Choclairs has a leading position in China's toffee candy category, according to internal sales data.
Media duties are handled by Carat China.