Chief innovation officer Herman Singh is expected to leave imminently, and will move on to start his own tech venture, said the people, who asked not to be identified as the information hasn't been made public. The exit will come as chief technology officer Babak Fouladi prepares to join Dutch telecommunications firm KPN in a similar role next week.
MTN confirmed Fouladi's departure, which was announced by Rotterdam-based KPN earlier this month. Singh declined to comment.
The executives are leaving after a three-year period of considerable turmoil at MTN. A shock $5.2bn fine in Nigeria in 2015 embroiled MTN in 10 months of negotiations and prompted a management overhaul. Then earlier this year, authorities in the West African nation announced another round of multi-billion-dollar demands.
The stock has halved over the period, valuing the carrier at R169bn. That's even as demand for data services in Africa booms and MTN expands in fast-growing services such as mobile money.
The shares declined a further 2% on Tuesday to R87.97 as of 12.10 in Johannesburg.
Team disbands
MTN chief executive officer Rob Shuter hired Fouladi two years ago from Vodafone in Spain as he assembled a new team in the wake of the first Nigeria penalty, which was eventually reduced to about $1bn.
Singh, formerly with MTN's crosstown rival Vodacom [JSE:VOD], was appointed in 2015.
Another of Shuter's appointments, Stephen Van Coller, left MTN at the end of August to take the helm of technology firm EOH Holdings.
Originally hired as head of mergers and acquisitions, the former banking executive was moved to run digital services before quitting less than two years into his tenure.
MTN's latest dispute with Nigerian authorities is over an allegation the company illegally transferred $8.1bn out of the country and owes $2bn in back taxes.
While the transaction matter looks close to being wrapped up, with Central Bank Governor Godwin Emefiele saying he's on "the verge" of announcing an amicable resolution, the taxation claim is still outstanding.
Other headaches for MTN include problems extracting cash from Iran, its third-biggest market, after US President Donald Trump reinstated sanctions against the country. The carrier has also come under pressure to list country units on local stock exchanges, with Uganda the latest to link a share sale to licence renewals.
