The energy company will work with Live Union on an initial three-week roadshow in September that will target around 600 staff.
The work is for EDF Energy’s B2C division, which includes customer-facing employees such as meter readers and call centre staff.
The roadshow is a chance for senior executives at EDF Energy to engage directly with employees and share updates.
It will be followed by a second roadshow – expected to take place in October and targeting 6,000 staff.
EDF Energy’s B2C communications and engagement manager Nicola Marsh said: "We have run employee events for a number of years and are looking to evolve them into a more collaborative platform, giving employees a more hands-on role and using the events to drive our wider internal communications strategy."
Live Union first worked with EDF Energy in 2010 and this win sees them becoming a rostered agency.
Marsh added: "Live Union demonstrated an incisive understanding of our desired outcomes and shared some brilliant content ideas and creative concepts."
Live Union was founded by Steve Eakins, Jez Paxman and Paul Watkins in 2009 and clients include Unisys, Trip Advisor and Metro.
Executive producer Paxman said: "We’re really looking forward to working with Nicola and her team, developing the content and devising new delivery formats that can be tailored to events around the country."