The Amsterdam-based agency was awarded the business without a pitch.
“Intersport is undergoing transformation and found a true agency partner in We Are Pi,” said Intersport International general manager marketing, Christoph Frechen.
“Together we have accelerated towards big brand strategy and creative consumer communications.”
The formal appointment followed project work that We Are Pi completed earlier this year to deliver Intersport comprehensive marketing insights, with internal stakeholder interviews supported by qualitative and quantitative consumer research.
Moving forward it will work with the agency to implement its biggest multi-year brand development push, with the first global brand campaign launching spring 2020.
We Are Pi is also working with Intersport on developing marketing excellence strategies in digital marketing innovation, editorial content and activation in partnership with local markets and key brands like Nike, Adidas, Puma and Asics.
Founder and chief executive, Alex Bennett-Grant said: “It's not often you get the chance to build a global brand for one of the largest and most important companies in the world of local sport. Intersport is a rare opportunity to genuinely affect change, at scale.”
In comes following the appointment of a new chief executive in Steve Evers, who replaced Victor V Duran at the company, which has a presence in 43 markets, earlier this year.
Intersport's sales reached €11.6bn in 2018 as sales increased 0.7%.
Last year, Intersport partnered with Alibaba to launch a ‘New Retail Megastore’ in Beijing.
The store featured a range of AI-driven features including AI-shopping assistants and smart mirrors, as well as interactive window displays, which recommended products based on gender and age. Smart Shelf technology, meanwhile, provided product information when a person interacted with items; including details for products not on display.