Global Tolerance wa\ill handle all communications for LifeLine, raising national awareness of its services.
The agency will position LifeLine as one of the only organisations that provides community services to people from the cradle to the grave.
It will also lobby ministers and public sector policymakers to persuade them to make use of LifeLine in the delivery of social enterprise projects.
The charity considered appointing an internal comms manager, but Global Tolerance will take up the mantle, following a four-way pitch against three other comms manager candidates.
The agency has been handed a 12-month contract. MD Simon Cohen will lead the account, reporting to LifeLine MD Ken Coello.
LifeLine recently won a national Financial Services Authority project that is designed to help young people provide mentoring services for their peers to help tackle youth debt. Global Tolerance will launch the project in January.