MindShare is tipped to win the &£10m pan-European account for the out-of-town retail and leisure centre operator Freeport.
The agency is believed to have won the business, worth about &£3m in the UK, following a pitch against Walker Media, Media Insight and AMS.
The retailer called a review of its media planning and buying business in February after reportedly sacking incumbent John Ayling & Associates.
RPM3 will continue to handle creative work for the company, which runs six out-of-town retail and leisure villages in the UK.
Freeport marketing director Simon Jobling refused to confirm the appointment as Marketing Week went to press.
Jobling was previously marketing director at video games developer Take 2 Interactive and joined the company this week.
He replaces Mark Hartstone, who left Freeport over a year ago. Since his departure, chief executive Sean Collidge has overseen marketing.
Freeport is investing &£200m in five shopping complexes in Europe, including a &£110m flagship site in Lisbon, Portugal, which will house a multiplex cinema and hotel. The first site to open on mainland Europe will be at Gothenburg in Sweden later this year.
Last month the company appointed Neil Thompson as group operations manager to oversee the running of UK sites and the European expansion programme.