The appointed agency will work on the flagship Guinness brand platform, "made of more", focusing on digital and shopper executions. Guinness has shortlisted agencies ahead of a pitch.
Saatchi & Saatchi won the global account in 2008 in the run-up to the brand’s 250th anniversary a year later.
The account does not include the brand’s global strategic work, which, as well as the Africa business, moved to Abbott Mead Vickers BBDO. Saatchi & Saatchi previously held both accounts. BBDO works with the brand in Northern Europe and the US.
Grainne Wafer, the global strategy and communications director at Guinness, said: "To drive better integration between idea generation and multichannel execution, we are looking to appoint a new agency to lead content creation across digital and shopper channels for our global platform, ‘made of more’.
"This agency will work directly with the global Guinness brand team and our existing regional agencies to help Guinness deliver its bold growth ambition globally."
Magnus Djaba, the chief executive of Saatchi & Saatchi London, said: "The rationalisation of tasks and agencies over the last couple of years have substantially changed the creative potential of the global Guinness account. As a result, we feel the time is right for us to part ways.
"We wish Diageo all the best in finding the right agency for the business going forward."