The new operating group will have one profit and loss line. John Wisbey will continue in the role of chief executive of the three agencies.
Publicis aims to offer clients collective thinking across direct marketing, publishing and interactive while maintaining specialisms.
It plans to work with clients early in the decision-making process in deciding which channels to use in communications activity rather than bolting on direct marketing or publishing later in the process.
Wisbey said: "This a move to the next stage. It didn't make sense to have three entirely separate businesses. Clients are asking more of us and are asking us to integrate our thinking but protect our specialisms.
He also said the change would enable Publicis to offer clients internal communications support because it will have a stronger mix of direct, digital and publishing.
Each agency will continue to run under the existing management teams.
Simon Marshall is the managing director of Publicis Dialog, Mike Williams is the managing director of Publicis Networks and Jason Frost is the managing director of Blueprint.
Publicis was a relative latecomer to investing in non-advertising services. All three agencies were launched over the past three years. However, group clients including Renault and Asda already use these services.