The story
American Urban Radio Networks, LLC was formed in 1991 from a merger of the Sheridan Broadcasting Network (SBN) and National Black Network (NBN). SBN was previously known as the Mutual Black Network (MBN) when it was founded by the Mutual Broadcasting System in 1972 as the first national full-service radio network aimed at African Americans. African-American media company Sheridan Broadcasting Corporation purchased 49% of MBN in 1976, followed by the remaining 51% in 1979, renaming it SBN.
Sheridan Broadcasting Corporation owned 51% of AURN, until it was forced to give up its share in 2016, following a lawsuit launched by junior partner NBN. Sheridan Broadcasting later went out of business.
From Wikipedia’s article on American Urban Radio Networks, shared under CC BY-SA 4.0.4