StrawberryFrog won the business in August last year in a shoot-out against McCann Erickson and WCRS, after Heineken decided to review the business out of Wieden & Kennedy Amsterdam.
Sir Frank Lowe, the founder of The Red Brick Road, has close ties with Charlene de Carvalho, the daughter of the former Heineken boss, Freddie Heineken, and the brewer has been expected to award the start-up some business since it launched earlier this year.
Clemmow Hornby Inge handles the UK account for the beer brand, but StrawberryFrog runs global activities such as the promotion of its sponsorship of the Uefa Champions League, for which the agency created a $100m campaign toward the end of last year.
Heineken refused to comment on the story.
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