The National Broadcasting Company (NBC) is an American commercial broadcast television and radio network serving as the flagship property of the NBC Entertainment division of NBCUniversal, a subsidiary of Comcast. The headquarters of NBC is in New York City at the Comcast Building. NBC also has offices in Chicago at the NBC Tower.
30 Rockefeller Plaza, the headquarters of NBC at Rockefeller Center in New York City
NBCUniversal Media, LLC is an American multinational mass media and entertainment conglomerate that is a subsidiary of Comcast and is headquartered at 30 Rockefeller Plaza in Midtown Manhattan in New York City.
NBCUniversal's headquarters at the Comcast Building (30 Rockefeller Plaza) in New York City
NBC Universal Chicago headquarters (NBC Tower)
10 Universal City Plaza (in Los Angeles County) in 2015 after Comcast acquired GE's remaining stake in NBCUniversal. Notice the wording on the top of the building changed. The Comcast headquarters can be seen at Universal Studios Hollywood.