As of 2013, the global advertising agencies of Omnicom Group and Interpublic Group, both based in Manhattan, had combined annual revenues of approximately US$21 billion, reflecting New York City's role as the top global center for the advertising industry, which is metonymously referred to as "Madison Avenue". The city's fashion industry provides approximately 180,000 employees with $11 billion in annual wages.
With Interpublic Group, what company has a combined annual revenue of roughly US$21 billion?
Omnicom Group