The brand, which is 12 months into a three-year strategy aimed at forging an intimate relationship between Diet Coke and the world of film, is planning a major TV ad campaign tied to an on-pack promotion that will urge consumers to vote for their favourite films.
The winning movies will be shown at special screenings at UGC cinemas around the UK, with tickets available to winning consumers.
A spokeswoman for Coca-Cola GB denied that a deal had been signed with UGC.
Earlier this year, Diet Coke unveiled an ad starring Hollywood actress Kim Basinger promoting a competition that offered consumers trips to film premieres.
Separately, UGC is involved in a promotional campaign announced this week by Pizza Hut, which sees diners offered a meal and two cinema tickets for £14.99.
It is being supported by a TV ad created by Abbott Mead Vickers BBDO.