Major U.S. commercial broadcasting company. It was formed in 1926 by RCA Corp., General Electric Co. (GE), and Westinghouse and was the first U.S. company to operate a broadcast network. Directed by RCA's president David Sarnoff, it became wholly owned by RCA in 1930. NBC was initially divided into the semi-independent Blue Network, based on station WJZ, and the Red Network, based on WEAF, each with links to stations in other cities. By 1938 the Red Network carried 75% of NBC's programs. The Blue Network was sold in 1941 and became the American Broadcasting Co. (ABC). NBC entered television broadcasting in a weakened position, and by 1952 it trailed CBS in audience ratings, though it gradually regained its leading position. In 1986 RCA was sold to GE; in 1987 NBC sold its radio networks. In the 1990s NBC expanded its cable television programming, creating MSNBC (an alliance with Microsoft) and CNBC (an alliance with Dow Jones).