Kakao Bank, a major internet-only lender in South Korea, said Wednesday its earnings shrank 17.7 percent in the second quarter from a year ago, citing an increase in its loan-loss reserves.

Net income came to 57 billion won ($43.3 million) in the April-June period, down from a net profit of 69.3 billion won a year earlier, the company said in a statement.

Operating profit fell 6.8 percent on-year to 74.4 billion won, and its revenue surged 46 percent to 371 billion won over the cited period.

The bank attributed the decreased net profit to increased loan-loss provisions.

But the bank said its net profit rose 6.8 percent on-year to 123.8 billion won in the first six months of the year. The figure marks the strongest-ever earnings since the bank's launch in 2016.

First-half operating profit also jumped 21.6 percent on-year to a record of 162.8 billion won.

Kakao Bank is an affiliate of Kakao Corp., the operator of the country's dominant messaging app KakaoTalk. (Yonhap)