Publicis Omnicom will have a combined equity market capitalisation of approximately $55.1bn with a combined annual revenue of $22.7bn.

Digitas, Big Fuel, Razorfish, Hall & Partners, Flamingo and Communispace are among the insight companies owned by Publicis and Omnicom and the ‘merger of equals’ will create a 130,000-strong workforce.

Among the reasons behind the merger, the two companies said that the changing competitive landscape and consumer behavior had created new client needs.

As a result, the merger would assist “leveraging investment in key marketing, data, analytics, and intelligence platforms”, according to a shareholder presentation.

Publicis chairman and CEO Maurice Lévy (pictured top) said: “The communication and marketing landscape has undergone dramatic changes in recent years, including the exponential development of new media giants, the explosion of big data, blurring of the roles of all players and profound changes in consumer behaviour.”

Subject to regulatory approval, Levy and Omnicom CEO John Wren will run Publicis Omnicom as joint chief executives for the first 30 months based in the Netherlands with operational headquarters in Paris and New York.