The six were expected to plead guilty and cooperate in the government's case, the New Orleans (La.) Times-Picayune reported Wednesday.
The investigation focuses on an $81 million contract between New Orleans and Milwaukee-based Johnson Controls Inc. that was intended to reduce city energy bills.
The six charged Tuesday include Stan "Pampy" Barre, a restaurateur and Morial confidant, who reportedly received $800,000 for little or no work.
Also charged were ex-city Property Management Director Kerry DeCay and former Johnson Controls Project Manager Terry Songy, who reportedly each received at least $100,000 in cash and gifts.
The charges add to June indictments against a former city official and three businessmen.
Morial, now president of the National Urban League in New York, has not been implicated in the scheme and repeatedly declined comment.
Notable deaths of 2014 [PHOTOS]