Some key events in NBC's history:
1926: National Broadcasting Co. formed by General Electric Co., Westinghouse Electric Co. and Radio Corporation of America after buying broadcast assets from AT&T. Launches first permanent radio network in United States.
1931: Experimental TV broadcasts begin from atop Empire State Building.
1932: RCA becomes sole owner of NBC.
1939: NBC begins regular television broadcasts in New York, with opening of World's Fair.
1941: NBC and CBS stations in New York get nation's first commercial television licenses.
1943: ABC gets its start after NBC sells one of its two radio networks under pressure from government.
1947: "Meet the Press" premieres.
1948: Comic Milton Berle becomes first television star on "Texaco Star Theater"
1948: Television ownership reaches 1 million.
1950: Trademark granted for three-note NBC chimes.
1952: Launch of "Today," first network early-morning news show.
1954: NBC makes first coast-to-coast color broadcast. "The Tonight Show" debuts with Steve Allen.
1962: Johnny Carson becomes "Tonight" host.
1964: NBC broadcasts its first Olympic Games.
1975: "Saturday Night Live" debuts.
1984: "The Cosby Show" debuts, becomes TV's biggest hit.
1986: GE restores its ties to NBC, becoming its owner after acquiring RCA.
1989: "Seinfeld" debuts.
1994: "ER" and "Friends" debut, making NBC's Thursday "must-see TV."
1995: Network launches NBC.com.
1996: NBC and Microsoft Corp. launch MSNBC on cable TV and Internet.
2002: NBC acquires Spanish-language broadcaster Telemundo and entertainment cable network Bravo.
2004: NBC Universal formed after merger with Vivendi Universal Entertainment.
2007: Jeff Zucker named president and chief executive.
2008: Launch of Hulu, online video joint venture with Fox network owner News Corp. ABC later joins.
2009: NBC, fourth in ratings and looking to pare the costs of producing scripted shows, brings Jay Leno to prime time. GE agrees to sell controlling stake in the company to Comcast Corp.
Sources: NBC, AP research