UM was brought on following a competitive review, which was supported by MediaLink. Hulu's media spend is in the hundreds of millions, according to people with knowledge of the matter.
Hulu brought all of its media planning and buying under one agency in an effort to unify its advertising strategy and planning across all channels.
Representatives from incumbents Razorfish and Zenith declined to comment. Razorfish handled the digital side of the business, while Zenith was responsible for all other media buying and planning.
This is the first agency review Hulu, a joint-venture between Walt Disney, 21st Century Fox, Comcast's NBC Universal and recent minority shareholder Time Warner, has conducted since its inception in 2007.
Hulu has grown up since it launched nine years ago as a way for people to catch up on episodes of broadcast TV shows the day after they aired. Still, it has plenty of work to do to distinguish itself from rivals Netflix and Amazon Prime.
To this end, the company, which has more than 12 million subscribers, has put an end to its free, ad-supported TV and movie offering, which has provided viewers with thousands of TV shows and clips.
It has also expanded into original programming, investing mightily to create high-quality content and securing exclusive streaming rights. And it is currently working on building its own cable-like TV package that will be streamed over the internet.