NCC orders MTN to pay $3.9 bln fine by Dec 31

South African mobile phone operator MTN will have to pay a $3.9 billion fine by December 31, 2015 imposed by the Nigerian Communications Commission NCC after failing to disconnect users with unregistered SIM cards.

"Appropriate action will be taken," should MTN fail to meet the deadline, a source told Reuters.

MTN said this month it would challenge the decision in court.