Its live music division, AEG Live, is to stage concerts by acts such as Back Street Boys and Aimee Mann over the coming year at venues across the UK.
Outside will promote the events to the music press, music columns in the national press and listings titles.
The agency reports to AEG Live international senior vice-president Rob Hallett, who is based in the company's recently opened London HQ.
Outside used to work with Hallett when he was at the Mean Fiddler Group from 2002 to 2004.
Freud Communications continues to handle AEG Live's corporate account.