The firm, whose brands include Budweiser, Boddingtons and Stella Artois, is understood to be holding 'chemistry meetings' with major agencies.
AB InBev has kicked off by discussing its Stella Artois account, but all 12 of its beer brands are believed to be up for grabs. One source said: 'They're hawking their way around London using Stella initially to see how people respond.'
Agencies that have worked for InBev in the past include Edelman, which handled a Stella Artois project, and Eulogy, which worked on a global Beck's brief.
InBev had not responded as PRWeek went to press.