The company has picked up the mobile and programmatic accounts from Somo and Mythings respectively. It will also handle content for Shop Direct.
Dentsu Aegis Network agencies Vizeum (media strategy and planning), Amplifi (investment) and The Story Lab (partnerships) already worked with Shop Direct. The media planning and buying account moved from Carat to Vizeum in 2014, after Carat won the business in 2004.
The company is now setting up a team called Pace with staff from Amplifi, Vizeum, John Brown Media, The Story Lab, Fetch (which handles mobile), and Data 2 Decision (marketing effectiveness).
Shop Direct spent £55.7m on media in the first three quarters of 2016.
Alex Baldock, group chief executive at Shop Direct, said: "Our customers love shopping on smartphone but they’re impatient. We’ve got just seconds to wow them and a five inch screen to do it on. That’s why mobile personalisation powered by our unique data asset is vital."
Shop Direct also owns Veryexclusive.co.uk and Littlewoods.com.
Tracy De Groose, chief executive of Dentsu Aegis Network UK & Ireland, added: "This allows us to work in a truly connected and collaborative way, to deliver different and better ideas, faster.
"Through our unique and powerful partnership and the creation of Pace, we hope to bring tomorrow’s thinking and insights to today’s marketing solutions."