Deezer appointed PrettyGreen in 2013 to manage its UK account, working alongside international agency Blue Rubicon. The international remit was handed over to PrettyGreen in August last year.
PrettyGreen did not repitch for the account, which is understood to be worth six figures.
Conor Maples, international PR manager at Deezer, told PRWeek: "We've reached a stage in our growth (second largest music streaming service in the world) where we have an excellent product, a hell of a lot of customers, and are playing an important role in building the new audio economy - but we know there is more work to do on making this brand famous and loved."
The appointed agency will be responsible for media relations, consumer activity, an influencer programme and being a central point of contact for Deezer's network of PR teams around the globe. They will be based in London.
Deezer's US activity will continue to be handled by Spark PR.
The service was launched in Paris eight years ago.