Omnicom Group will acquire Interpublic Group, the companies confirmed, in a deal that will create the world’s largest advertising business. Under the all-stock deal, Omnicom would exchange 0.344 shares for each Interpublic share,

Interpublic Group of Companies shares are surging in premarket trading after Omnicom Group said it had struck a deal to acquire its rival in an all-stock deal that would form the world's largest advertising company.