JWT has held the account since April 2008, when it beat Leo Burnett and Bartle Bogle Hegarty, the previous incumbent, to win the business.
The agency's relationship with Smirnoff, another Diageo brand, is unaffected.
JWT produced some high-profile ads for Baileys during its time working on the account of which the last was a TV spot called 'Treat Yourself Tonight'. The ad featured a close-up of a woman's lips as she sung the song 'Night And Day' by Ray Charles.
The agency also created another TV ad that saw Baileys being splashed on to a woman's lips. It hit the headlines after some viewers complained that the content was close to the imagery found in some pornographic films.
In January, Diageo called a pitch for its CRM business in China, with at least three agencies vying for the account.
In 2008, Baileys rolled out a campaign in Hong Kong to build interest in its revamped bottle packaging and two new flavours: Baileys with Creme Caramel and Baileys with Mint Chocolate.