The charity, which works to help develop more sustainable cities and communities around the world, is seeking support for its WeastFlows campaign, a four-year transport and logistics scheme around freight travelling from West to Eastern Europe and beyond.
The £7.8m project will focus on making freight and logistics more efficient and sustainable, and involves 23 European-based partners.
It is understood that the charity has now shortlisted three agencies after receiving eight responses to the brief.
WeastFlows project manager Mark Thirkell said: 'The project is classed as a strategic initiative, which means that we are required to communicate and disseminate the profile and output of the project at a much higher level.
'The successful agency will be required to communicate with MEPs, European commission officials and our partners.'
Thirkell added that the institute would be seeking further comms support in the New Year. The winning agency, which will be taken on for an initial 12-month contract, will be charged with developing the existing comms strategy and creating materials for the project. In addition,the agency will help the institute to comply with the sponsor's specific branding requirements and assist with brand development.