London-based advertising and public relations giant WPP Plc said it merged its units Burson-Marsteller LLC and Cohn & Wolfe Inc. into a new entity dubbed Burson Cohn & Wolfe.

Donna Imperato, CEO of Cohn & Wolfe, will take the reins of the new entity. Burson-Marsteller CEO Don Baer will be the chairman.

Cohn & Wolfe is a global communications agency established more than 45 years ago. Burson-Marsteller is a global public relations and communications firm established in 1953.

A group of executives from both merging units has been formed by Imperato to ensure a smooth post-merger integration.