Kollat previously headed up the media product management team for eCircle. In his new role Kollat will take responsibility for the entire media division.
He will be responsible for a team of 30 whose roles are focused on email campaigns, which offer clients access to more than 80m opt-in email addresses, and lead generation.
In his previous position Kollat was responsible for growing the product management departments for eCircle's offices in Germany, Italy, France and the UK. Before joining the firm he worked at Kodak in Germany.
Kollat, whose promotion comes just weeks after the appointment of Simon Bowker as eCircle's UK managing director, said: "[The company's media division] allows brands to build a warm database of prospects enabling them to start dialogues with key groups of consumers".
Volker Wiewer, co-chairman of the executive board at eCircle said Kollat has been a "great asset" to eCircle and welcomed him to the new role.
Wiewer said: "With his valuable experience and knowledge of email list rental, list broking and campaign management he will undoubtedly drive our offering in the UK market to another level."