The development was announced today to shareholders at the Johannesburg Stock Exchange.
The MTN statement reads: “MTN wishes to inform the market that MTN’s Chief Executive Officer, Mr. Sifiso Dabengwa has resigned.
“Due to the most unfortunate prevailing circumstances occurring at MTN Nigeria, I, in the interest of the Company and its shareholders, have tendered my resignation with immediate effect,” stated Sifiso Dabengwa.
Dabengwa, born in Zimbabwe joined the MTN Group in 1999, where he held various jobs before he became Chief Executive Officer in 2011. He holds a B.Sc. in Electrical Engineering, an MBA and EDP.
While MTN said it would continue talks with authorities in Nigeria over the fine, a non-executive chairman and former CEO, Phuthuma Nhleko has been appointed as executive chairman for a maximum of six months.
The Africa's biggest mobile phone company was fined in October by the Nigerian telecoms regulator for failing to cut off 5.1 million users with unregistered SIM cards after the expiration of a fixed date. The regulation stipulates N200,000, about $1,000 fine for un-disconnected line.
Shares in MTN have slid about 17 percent since Oct. 26 to 157 rand by Friday, following news of the charge.
Ratings agencies Moody's and Fitch lowered MTN's credit rating outlook to "negative" last month flagging the risk of significant cash outflow and the likely damage to the Nigerian business due to lengthy talks.
The new executive chairman, Nhleko (born 7 April 1960), a South African businessman,is also chairman and one of the founding members of Worldwide African Investment Holdings, an investment holding company with interests in the petroleum, telecommunications and information technology industries. He helped build the company to a book value of investments of about R3,5bn.
He was previously a senior member of the Standard Corporate & Merchant Bank corporate finance team. He also practised as a civil engineer and project manager for the Urban Foundation, and was a senior road engineer for the Ministry of Works in Swaziland.
Nhleko is a director of Johnnic Holdings, Nedbank Group and Old Mutual SA.
Nhleko's academic qualifications include a BSc in civil engineering from Ohio State University and an MBA in finance from Atlanta University.