The head of the Illinois' largest charter school operator is stepping down following concerns about nepotism, bonds and conflicts of interest.
Juan Rangel resigned as CEO of Chicago's United Neighborhood Organization.
His resignation was effective immediately and comes months after Rangel's top aide resigned.
Federico d'Escoto left UNO in February after the Chicago Sun-Times reported that $8.5 million had gone to companies owned by his relatives.
State officials briefly cut off funding for a $98 million state construction grant until Rangel apologized and introduced a new board of directors. But the money was suspended again when federal officials began examining UNO's bond dealings.
Rangle was co-chairman of Rahm Emanuel's successful 2011 Chicago mayoral campaign.
UNO's network has more than 7,600 students in 16 charter schools.