Bharti Airtel this week reported a 30.8% decline in fiscal first-quarter net profit, due to foreign exchange losses caused by the devaluation of the Nigerian naira.

The India-based telco’s net profit for the three months to 30 June came in at 14.62 billion rupees (€198.09 million), compared to INR21.13 billion in the same quarter a year earlier.

In a statement on Wednesday, Bharti Airtel said its income was hit by a 42.1% fall in the value of the naira, resulting in a net forex loss of INR7.48 billion. Forex losses from other markets improved to INR3.09 billion from INR7.97 billion a year ago.

Group revenue jumped 7.9% to INR255.46 billion (€3.46 billion), and EBITDA climbed to INR95.91 billion from INR82.4 billion a year earlier.

At its domestic business, revenue grew 10.3% year-on-year to INR191.55 billion, while EBITDA increased 17% to INR81.96 billion. Mobile data revenues were up 35.1% to INR35.35 billion. The operator ended June with 255.74 million mobile customers in India, up from 230.66 million a year ago.

At Bharti Airtel’s Africa business, which reports in U.S. dollars, revenue increased 2% on-year to $935 million (€850.62 million). EBITDA grew to $210 million from $187 million. Data revenue surged 31.2% to $154 million. However, the company’s African customer base slipped to 76.99 million from 78.32 million, driven by the implementation of customer-registration rules in a number of markets.