Shares of global telecom company MTN plunged to 41 percent this year, its lowest level since 2009 on Thursday.
It follows an order by the Nigerian central bank to the company to transfer some $8.1 billion, it said it had moved out of the country illegally.
It accuses MTN of using improperly issued central-bank certificates to move money out of the country to South Africa between 2007 and 2015.
MTN’s stock slumped 24 percent to 81.80 rand as of 12:39 pm in Johannesburg, valuing the South African company at 153 billion rand or 10.5 billion US dollars.
MTN chief executive officer, Rob Shutter has refuted all claims saying due process was followed.
But an analyst told bloomberg that an immediate concern for investors is that MTN will not be able to repatriate funds out of Nigeria while the dispute is unresolved.
This means the Johannesburg-based company may have to cut dividend, the analyst said.