African telecommunications giant MTN says Nigeria is extending Monday's deadline for it to pay a $5.2 billion fine.

A statement from the South African-based company says the fine will not be paid until negotiations are concluded with the Nigerian Communications Commission.

MTN CEO Sifiso Dabengwa resigned last week over the fine, imposed for failing to meet a deadline to deactivate 5.2 million unregistered SIM cards, a security issue in Nigeria. Authorities say cell phones are used to coordinate attacks by Boko Haram Islamic extremists as well as in rampant kidnappings and armed robberies.

MTN shares have slumped. Nigeria's 60 million-plus MTN subscribers provide about one third of profits for MTN Group, which has 233 million subscribers in Africa, Asia and the Middle East.