South Africa-based operator group MTN said investors should be braced for a fall in earnings when it announces interim results next month (5 August).

The company blamed adverse exchange rate movements for a forecast drop of between 10 and 15 per cent in attributable earnings per share for the six months to end-June, over the same period in 2014.

The unkind currency movements affected the rate at which revenue and EBITDA were changed, said the company, and was worse hit than 2014.

The main culprit was MTN Nigera, the group’s largest operation where the currency has fallen sharply. The Nigerian operator was also a victim of a fuel shortage the country suffered in May. Despite being an oil exporter, Nigeria lacks domestic refining capacity so experienced fuel shortages at home, which impacts economic activity (and mobile usage).

Although not highlighted in MTN’s statement, the operator has also had problems domestically – South Africa is its second-largest market – where it only recently managed to end a damaging two-month strike.