The N1.04trn fine imposed on the MTN Group by Nigerian Communications Commission (NCC) has been reduced to $3.4 billion.
MTN is expected to pay the new sum by December 31.
NCC imposed the fine on MTN in October after the mobile operator failed to cut off users with unregistered SIM cards from its network.
There have been persistent worries that the unregistered SIM cards were being used for criminal activity in a country facing the insurgency of Islamic militant group Boko Haram.
Meanwhile, MTN Group confirmed the fine reduction, as well as the resignation of Michael Ikpoki, MTN Nigeria’s chief executive officer (CEO) and the head of regulatory and corporate affairs Akinwale Goodluck.