Camelot, the operator of The National Lottery, awarded its £40 million planning and buying business to Vizeum last week.
The win is the biggest in the agency’s history, ahead of the £34 million 20th Century Fox account it picked up in 2007.
Dentsu Aegis Network divisions that will work with Camelot include the search specialist iProspect, the measurement and marketing effectiveness unit Data2Decisions, the outdoor agency Posterscope, the investment arm Amplifi and the insight panel Consumer Connections System.
Digital integration will be a focus for Camelot’s marketing, in line with a new strategy of bringing its four products under the "play makes it possible" proposition.
Vizeum landed the account after beating OMD in a final shoot-out. The business was previously shared by OMD, which handled buying, and Havas Media, which worked on planning.
Havas was knocked out at an earlier stage in a process managed by Oystercatchers.
Sally Cowdry, the marketing and consumer director of Camelot, said: "Vizeum has a fantastic track record across both the traditional and digital media landscapes, and presented some truly unique and exciting ideas.
"We are very much looking forward to working with them on our new integrated media brief."