Turner Broadcasting has handed its $150m (£90.5m) media planning and buying account to Horizon Media.
Incumbent MediaVest was not invited to pitch for the account, with Dennis Camlek, SVP for Turner Media Group at Turner Broadcasting saying it was time to make a change.
“We worked with them for five years, which says a lot,” he added.
Horizon will handle media buying for CNN, TNT, Cartoon Network, Turner Sports and TBS following the pitch against two other agencies, in a process which was handled in-house.
The agency will begin working for Turner at the start of 2015.