He is said to have lined up as much as £100m in financing from a private equity backer for his planned, new company, which has been codenamed Project Oak, and he has recruited Don Elgie, the former chief executive of the listed marketing group Creston, to be chairman.
Graham is targeting agencies in data, performance, media, insight, customer relationship management and content and he pointed to the success of Merkle, the US digital marketing group that has just sold a majority stake to Dentsu Aegis Network for $1.5bn.
Industry sources said Graham has been meeting informally with dealmakers in London in recent weeks to discuss their appetite for potential acquisitions.
Graham said: "There’s a huge opportunity to bring together a modern group of agencies which have a common understanding of data and digital.
"If we can bring them together under one roof and get them collaborating, we think we can produce a more effective and cohesive offering for clients."
A former executive at WPP and Omnicom agencies, Graham claimed the big ad holding groups "don’t collaborate" internally because they are structured as silos.
"We think there’s a way to break down silos and connect the dots through data," he said.
Graham declined to comment on how much money he has lined up or reveal the identity of his planned private equity backer.
It is a competitive market. A number of private equity backers have invested in marketing services groups, including Chime, Engine Group and Karmarama, and another small group, Be Heard, floated as an acquisition shell on the London Stock Exchange last year.
Several leading consulting and software firms, including Deloitte, Accenture and IBM, have also been buying marketing agencies.
Graham maintained he has the "entrepreneurial brain" to lead his planned group.
He was a founding member of digital agency Saint, a subsidiary of WPP’s Rainey Kelly Campbell Roalfe/Y&R, before heading Weapon7, a subsidiary of Omnicom’s Abbott Mead Vickers BBDO.