Currency constraints in Nigeria have hampered MTN's ability to repay loans in the past year, but despite the challenges in the West African nation the company is considering listing on the Nigerian Stock Exchange.
About R25-billion was held in Nigeria, the largest contributor to MTN's earnings out of the group's 22 markets, Brett Goschen, MTN's chief financial officer, said after the group's results presentation this week.
"It's difficult to access forex in and out of Nigeria," Goschen said. As a result, MTN Nigeria defaulted on dollar-denominated loan repayments in Nigeria last year, when it was unable to get access to funds to R991-million.
The Nigerian economy is struggling after global oil prices plunged to under $30 per barrel in 2015.
Nigeria's central bank controls the naira exchange rate and keeps it steady by restricting access to other currencies.
William Jackson, an analyst at Capital Economics, said: "The obvious thing for the central bank [is] to let the official naira rate weaken and hike interest rates to shore up capital inflows. Ultimately we think this will happen when the market forces the [monetary policy committee] to act. But it's unlikely to happen this month."
An MTN insider said the Nigerian currency situation had hampered the payment of suppliers.
However, Goschen said MTN had "put in place measures to ensure that it doesn't affect the company" in future.
Group executive chairman Phuthuma Nhleko said MTN would keep its primary listing on the JSE. "We've demonstrated that you don't have to be a London-listed company to be successful," he said.
Already, 22% of MTN's shares are traded over the counter in Nigeria.
Nhleko, who did not give a date for the listing, said the only hurdle was the unresolved matter of a punitive $3.9-billion fine for not disconnecting unregistered sim cards in Nigeria timeously.
MTN has set aside $600-million to pay the fine. It paid $250-million last month as a goodwill gesture and withdrew its court case against the Nigerian authorities, which enabled settlement negotiations to continue.
President Jacob Zuma will pay a state visit to Nigeria this week. It is unclear whether MTN will be on the agenda in talks with Nigerian President Muhammadu Buhari.
MTN's regulatory challenges in Nigeria include the withholding of regulatory services, meaning the company could not implement new tariff plans in Nigeria. This was one of the reasons behind a 51% decline in group earnings to R7.46 per share for the year to December. Group revenue was flat at R146.4-billion.
Capital expenditure for 2016 will be R31-billion, of which just over a third will be spent in Nigeria to improve network quality. MTN intends to roll out optic fibre for internet service to homes in Nigeria and Iran, as well as in South Africa.
CORRECTION: MTN is considering listing in Nigeria but has not yet established firm plans, contrary to what we stated in a previous version of this article. In addition, the company said R25-billion in cash was held in Nigeria, not $22-billion. The headline has been changed to reflect this. We regret the errors.