Three UK has appointed Zenith as its UK media and planning agency in a move that will displace longtime partner Mindshare, which has worked on the brief since 2006.
The telecom giant said that Zenith will work "hand-in-hand" with its interal marketing team as it seeks to win the battle to become market leader for 5G tariffs.
The media agency will pick up the contract at the start of 2020 and will be responsible for media planning and buying across all channels including TV, out-of-home, press, digital and social media.
Zenith joins Wieden & Kennedy London, Pretty Green, MRM and Gravity Road on Three's roster as the brand continues to roll out its 5G offering to UK customers.
Shadi Halliwell, chief marketing officer at Three, said: “The way people consume media is changing and our brand continues to evolve and grow. Our aim was to find an agency partner who truly understands how customers engage with media. Zenith demonstrated a solid understanding of our needs through an innovative and disruptive approach."
She added that 2020 presented a huge opportunity for Three to pave the way with its 5G proposition within the connectivity market.
"Like all our agency partners, Zenith will become an extension of the Three marketing team, joining us as we move into a leadership position through our 5G offering."
Three is a big spender on platforms like Instagram and Snapchat as well as on traditional mediums.
Known for its tongue-in-cheek tone, the brand has most recently been focused on touting the message that ‘Phones Are Good’, weighing in on the topical debate that ‘phones are bad’ by reimagining pivotal moments in history.