Juan Rangel, head of the UNO charter chain, resigned his position as CEO. 

UNO is the largest charter chain in Illinois.

Rangel’s departure “by mutual agreement” with the board of the not-for-profit group is effective immediately, UNO officials said Friday.

Rangel had three family members on the UNO payroll. Sources said two of the relatives quit recently, including deputy chief of staff Carlos Jaramillo, Rangel’s nephew.

Reached by phone, Rangel hung up on a reporter.

Rangel has close ties to politicians including Mayor Rahm Emanuel, whose 2011 campaign Rangel co-chaired, Ald. Edward M. Burke (14th) and Illinois House Speaker Michael Madigan (D-Chicago), who sponsored a $98 million state school-construction grant to UNO in 2009 that has fueled its rapid growth as a charter-school operator.