SingTel's share of Bharti Airtel's losses in Africa led to a decline in profit for the company's fourth quarter.
SingTel said its net profit fell 2% to S$992 million ($802 million), but that excluding the impact of Bharti Africa profit would have grown 1%.
The performance of Bharti Airtel, in which SingTel owns a 32.25% stake, and its other regional affiliates undermined a strong performance in Australia and stable growth in Singapore.
SingTel subsidiary Optus grew its revenue 5.3% in Singapore dollar terms to S$2.98 billion, with mobile service revenue growing 7% and postpaid net additionsreaching 151,000.
Revenue from Singapore grew 1.3% to S$1.66 billion, and mobile revenue grew 9% to S$455 million.
But pre-tax earnings from regional affiliates Telkomsel, Bharti Airtel, AIS, Globe Telecom, Warid and PBTL declined 12% to S$479 million.
The strength of the Singapore dollar against the regional currencies was partly to blame, but contributions from India's Bharti, Indonesia's Telkomsel, and Bangladesh's PBTL all declined in local currency as well.
For the full year, profit fell 2.1% to $3.825 million, even as group revenue increased 7.1% to S$18.1 billion.
The SingTel group added 110 million mobile customers during the financial year, surpassing 400 million for the first time.
Bharti is responsible for the majority of customers at nearly 212 million, with Indonesia's Telkomsel growing to 99.3 million and Thailand's AIS to 31.9 million.
Subscribers in Singapore grew to 3.3 million from 3.1 million, while Optus customers grew to 9.1 million from 8.5 million.
Bharti's own full-year profit fell 32.6% due partly to its losses in Africa, the company revealed last week.