JOHANNESBURG, March 1 (Reuters) – Africa’s biggest telecoms operator MTN Group MTNJ.J flagged on Friday an up to 80% fall in full-year profit as a sharp devaluation in the Nigerian naira pushed its biggest unit MTN Nigeria MTNN.LG to a loss.

South Africa-headquartered MTN said its headline earnings per share – one of the main profit measures – would fall between 60% and 80% in the year ended Dec. 31 from 1,154 cents a year earlier.

Nigeria’s central bank in June adopted new forex rules that MTN said had since led to an approximately 96.7% devaluation in the exchange rate to 907.1 naira per dollar by the end of December.

The operator said the devaluation drove higher operating and net finance costs and foreign exchange losses for MTN Nigeria, which are expected to impact the group’s financial performance.

MTN Nigeria reported a net forex loss of 740.4 billion naira ($569.54 million) in 2023, raising its net finance costs 341.9% to 951.5 billion naira.

MTN Group shares fell 7% in morning trade before paring losses to stand 1.20% lower by 1236 GMT with the group saying it still expects to declare a dividend in line with guidance of a minimum 330 cents per share.

Shares in MTN Nigeria tumbled 9.96%.

MTN Nigeria reported a loss after tax of 137 billion naira compared to a restated profit after tax of 348.7 billion naira in 2022.

The Nigeria operator withheld its final dividend for 2023 and also suspended is medium-term guidance for earnings before interest, tax, depreciation and amortisation margins.

($1 = 1,300.0000 naira)

(Reporting by Nqobile Dludla; Editing by Mrigank Dhaniwala, Kirsten Donovan)