New York--Interpublic Group of Cos.â Hill, Holliday, Connors, Cosmopulos announced Monday that it has agreed to acquire New York-based Frankfurt Balkind, a marketing communications agency. With the acquisition, Hill, Holliday hopes to add to its current services in the areas of strategy, identity and digital communications. Frankfurt Balkind clients have included Sony, Pitney Bowes, Knight Ridder and Schering-Plough. Aubrey Balkind will retain his title of president of the Frankfurt Balkind division. Financial terms of the deal were not disclosed.