Telecoms operator, MTN Group Limited, is planning to raise about N153bn ($500m) from the sale of shares in its Nigerian business during the first half of this year, fulfilling the terms of a deal struck with the country to settle a record fine, Bloomberg has reported, quoting people familiar with the matter.

Standard Bank Group Limited and Citigroup Incorporated have been advising Africa’s largest mobile phone company on the disposal of as much as 30 per cent of the Lagos-based unit on the Nigerian Stock Exchange, the sources said on Wednesday.

The sources pleaded anonymity as the details of the listing had not been made public. Most of the shares will be sold to local institutions and individuals, though foreign investors could be brought in to ensure the process is a success, one of the people said.

Discussions are ongoing and a final decision hasn’t been made, they said.

Spokespeople for MTN and Citigroup in Johannesburg didn’t immediately comment, and Standard Bank didn’t immediately respond to Bloomberg calls seeking comment.

MTN agreed to list the Nigerian unit as part of a June 2016 agreement to pay a $1bn fine for missing a deadline to disconnect unregistered subscribers amid a security crackdown. The penalty, originally set at $5.2bn, led to the resignation of the Johannesburg-based company’s then chief executive officer and a slump in the share price that’s yet to be clawed back.

The stock extended gains and traded 4.5 per cent higher at 128.83 rand as of the close in Johannesburg, giving a market value of 243 billion rand ($20bn).

If successful, the share sale will be the biggest on the Nigerian Stock Exchange after Starcomms Plc, which raised $796m when it listed in 2008, according to data compiled by Bloomberg.

MTN, Nigeria’s biggest mobile phone company with just over 50 million subscribers as of end September, slumped to a loss in 2016 as it absorbed the financial impact of the fine, though it said last month that it returned to profit the following year.

Nigeria and other sub-Saharan African governments are trying to gain more from international mobile phone operators taking advantage of rising smartphone use and faster data speeds. MTN has also agreed to sell shares in Ghana as one of the conditions of a deal to gain spectrum rights, while Vodacom Group Limited, South Africa’s market leader, was ordered to list 25 per cent of its Tanzanian business last year, raising $213m.

A top official of the Securities and Exchange Commission recently told The PUNCH that the commission had yet to receive any document from MTN indicating an interest to list.

The official said the department concerned with new listings on the local bourse was not in possession of any document showing that MTN had a listing programme on the NSE.

The Chief Executive Officer, NSE, Mr. Oscar Onyema, told journalists mid-January this year that the Exchange would not comment on the planned listing of MTN as it was not in the right position to speak for the telco.

“MTN has to tell its own story, and not us doing so for it,” Onyema stated.