The federal court panel considered the case for about six hours Sunday but reached no verdict.
Members said Saturday that they were at an impasse but were told to continue to try to reach agreement.
The jury began deliberations Jan. 8 but endured setbacks when two jurors left because of illness or conflicts.
It remains unclear whether they have resolved some of the approximately 50 counts against seven defendants, including reputed boss Joseph "Uncle Joe" Ligambi and underboss Joseph "Moussie" Massimino.
The defendants are accused of sports betting, loansharking, operating illegal video poker machines and threatening debtors. The evidence includes years of FBI wiretaps and undercover work, but there's no violence alleged.