
The WPP agency impressed the awards judges with its considerable growth in the past year - becoming the first media agency to pass the £1bn billings landmark - but also through its regional growth in Scotland.
MediaCom was also singled out for a consultancy partnership with Thinkbox, its Carbon Neutral Project and its Word of Mouth client initiative.
Despite losing its Agency of the Year crown, Carat enjoyed a good night, scooping the prestigious Grand Prix award for Adidas' London Marathon campaign.
Carat used Adidas' "Impossible is Nothing" mantra to inspire a campaign to raise awareness of its sponsorship of the Marathon and help spectators track friends and family running in the race.
After quizzing athletes, Carat delivered 5,250 messages of support to the 25,000 runners.
The activity also won the Media Idea (Niche) award - for campaigns under £250k - for its work on Adidas' London Marathon activity, beating Manning Gottlieb OMD, OMD UK, I-Level and Vizeum UK in the final shoot-out.
MediaCom scooped the Media Idea (Medium) award for campaigns of between £250k and £1m for its work on Aquafresh: The Nurdles. It won the award in a final showdown against OMD UK, Goodstuff and Mindshare.
Judges were impressed by the activity - a 90-second film called The Nurdle Schmurdle - which aimed to help mums persuade their children to brush their teeth and go to bed.
Universal McCann picked up the gong for best international campaign, for its work on the Xbox game Halo 3: Believe.
Winners in full:
Media Agency of the Year
MediaCom
Grand Prix
Carat
Adidas - London Marathon
Media Idea Large
Starcom
Honda Accord: Difficult is Worth Doing
Media Idea Medium
MediaCom
GlaxoSmithKline: Aquafresh
Media Idea Niche
Carat
Adidas - London Marathon
Sales Team of the Year
Viacom Brand Solutions
Sales Pitch Large (over £1m)
Classic FM
Ford: Galaxy of Stories
Sales Pitch Medium (£250k - £1m)
Turner Media Innovations
GlaxoSmithKline
Aquafresh: The Nurdles
Sales Pitch Niche (under 250k)
Bauer Radio Events
One Scotland
Rock Against Racism
Media Innovation
ITV
eBay
Bringing eBay's Live Marketplace to Life
International ±±¾©Èü³µpk10
Universal McCann
Xbox
Halo 3: Believe
Best Research Initiative
IPC Media
The Origin Panel
Collaboration
News Group Media with TalkSport, MediaCom, ZenithOptimedia, Abbott Mead Vickers BBDO, JCPR and Mars
Mars
Balls
Media Brand of the Year
Dave
UKTV and IDS
Rising Star
Juliet Kennard
Times Media