Kellogg's appointed the agency in July to deliver a three-day conference for 350 delegates in the Midlands later this year.
HGA Creative Communications live events director Ian Grime said: "We are not looking at conventional venues. They want to do something radically different."
The agency also won business from Shop Direct Home Shopping in June, following a pitch against at least three other agencies.
It will deliver a conference for 1,000 delegates at the ACC Liverpool on 15 September.
The event will include fashion shows and brand and advertising presentations.
A gala dinner with awards and an X Factor-style talent contest will be held in the venue's exhibition hall.
The home shopping company, whose brands include Littlewoods and Woolworths.co.uk, is exclusively hiring the venue for the two-day event.