SEOUL, Nov. 4 (Yonhap) — Kakao Bank, South Korea’s top internet-only lender, said Wednesday its third-quarter earnings spiked sevenfold from a year ago on increased interest income.

Net profit came to 40.6 billion won (US$35.9 million) in the July-September period, compared with 5.8 billion won from a year earlier, the lender said in a regulatory filing.

In the first nine months of the year, the bank’s bottom line rocketed 458 percent on-year to 85.9 billion won.

Kakao Bank, controlled by Kakao Corp., operator of South Korea’s dominant messaging app KakaoTalk, attributed the stellar third-quarter performance to more interest income and the first shift to profit by its non-interest business.

The lender’s interest income totaled 107.9 billion won in the third quarter, with its fee income coming in at 4.1 billion won.

As of end-September, Kakao Bank’s outstanding loans stood at 18.7 trillion won, up 1.4 trillion won from three months earlier, with its assets totaling 25 trillion won.

Its net interest margin, or the difference between interest paid and interest received, came to 1.64 percent with the loan delinquency rate reaching 0.23 percent.

Kakao Bank’s capital adequacy ratio, a key barometer of financial soundness, amounted to 13.45 percent as of end-September, down from 14.29 percent three months earlier.

In 2017, Seoul allowed two internet-only banks — Kakao Bank and K-Bank — to offer services around the clock in a bid to inject more competition into the banking sector.