Starcom previously only worked on the buying assignment, with the planning briefs split among three media agencies - Universal McCann, Mediaedge:cia and Hakuhodo.
Coca-Cola's Hong Kong external affairs manager Elsie Tsui said: "The aim of the review is to follow a new approach to handle a cross-portfolio of brands to achieve better efficiencies."
Starcom Hong Kong general manager Mabel Leung added: "The pitch focused on three main areas: consumer insight, effective communications strategy and portfolio management."
There was no change to the roster of creative agencies, which includes McCann-Erickson, Ogilvy & Mather and Hakuhodo.
Starcom's win of the Coke consolidation pitch in Hong Kong means that the agency now has the beverage giant's entire Greater China media business.
The network has long held the Taiwan brief and, late last year, it picked up the China assignment, worth between $30 million and $50 million, from ZenithMedia.