South Africa-based MTN confirmed talks are ongoing with Nigerian authorities over a massive fine imposed for failing to register the personal details of 5.1 million subscribers.

“As per our SENS [Stock Exchange News Service] announcement, the company reiterates that engagements with the Nigerian authorities are continuing and any material developments in these engagements will be communicated to shareholders through SENS,” read a MTN statement.

Earlier, the Johannesburg Stock Exchange (JSE) suspended trading in MTN shares, pending an announcement by the company. Shares fell steeply on speculation that the company had agreed to pay the $5.2 billion penalty, which was imposed last week.

“Shareholders should specifically exercise caution when reacting to information on this matter which has not been released by the company,” warned the MTN announcement.

“Shareholders are therefore advised to continue to exercise caution when dealing in the Company’s securities until a further announcement is made,” it added.

On Friday, the Nigerian telecoms watchdog gave MTN until 16 November to pay the massive fine.