The first and elder three (which are colloquially known as the "Big Three") began as radio networks: NBC and CBS respectively began operations in 1924 and 1927, while ABC was spun off from NBC to Edward J. Noble in 1943 as the Blue Network during FCC inquiries over NBC's dominant share of the American radio market, although the ABC television network would not reach viewership and distribution parity with NBC and CBS until the late 1960s.