Hope&Glory PR will promote the arrival of US channel truTV, which is scheduled for 4 August.
It is the first foray into free-to-air broadcasting in the UK by Turner, which is home to channels including Cartoon Network, Boomerang and CNN International.
The PR programme will include a full range of activities including pre-launch features, a major UK media launch event, stunts and engaging with influencers.
Support for individual shows, which include Conan, Killer Karaoke, Fear Factor and Container Wars, will also be part of the brief.
The team will be headed up by Hope&Glory managing partner James Gordon-MacIntosh and will report to Turner Broadcasting’s EMEA director of communications and marketing, Charlotte Chisnall, and UK PR manager Victoria Westwood.
Chisnall said: "We wanted a team that would on the one hand deliver creative ideas and stunts to get people excited about truTV, but also bring rock-solid support for the day-to-day media relations."