On Monday, MTN said it had turned to the courts for relief in its dispute with the Nigerian authorities, which have ordered the mobile operator to return $8.1bn in dividends.
Nigeria says the funds were repatriated illegally.
Africa’s biggest mobile operator by subscribers is also accused of owing Nigeria $2bn in outstanding taxes.
MTN said in a statement that it had applied for injunctive relief in the federal high court of Nigeria, restraining the Central Bank of Nigeria and attorney-general of Nigeria from enforcing the damaging claims.
Its shares have lost just more than a third of their value on the JSE since the claims surfaced just more than three weeks ago.
MTN’s troubles in Nigeria highlight the risks in its business, with operations in difficult markets such as Syria and Afghanistan often shunned by multinational rivals.
In July, MTN was hit by US President Donald Trump’s sanctions on Iran, meaning it may be unable to repatriate R3.4bn from that country.
MTN shares were down 0.80% to R74.13 in late trade, giving it a market value of R139.6bn.
With Giulietta Talevi