Rising interest rates have sent the net profit of banks soaring, results out Tuesday show. Among the Big Three banks in Korea, Woori Bank stood out, racking up a bumper W749.8 billion (US$1=W1,162) net profit from January to September this year. Kookmin Bank recorded W618 billion and Shinhan Bank W564.6 billion.

The roles have been reversed from last year, when Kookmin made W1.83 trillion, Shinhan W1.09 trillion, and Woori W925.1 billion.

From the beginning of the year until the third quarter, Woori made the most net profit per employee with W50.47 million per worker, followed by Shinhan's W43.53 million and Kookmin's W24.01 million. Woori clearly outperformed the other two in the third quarter, making a W410 billion net profit compared to W288 billion by Shinhan and W231.2 billion by Kookmin.

The total assets of the three banks do not differ greatly at around W250 trillion, and all three greatly benefited from rising interest rates applied to loans. Then what explains the difference? The other two argue that it is not because Woori Bank had better sales strategy and insist it is a one-off as Woori earned W140 billion by selling off its IT center in Jamsil, southeastern Seoul in June.

Woori Bank disagrees. It says since the global financial crisis last year, the era of loan sales came to an end, and it is now the time to focus on selling savings packages, which Woori says it has focused on. But instead of regular savings account, where banks are required to pay high interest to customers, Woori says it worked hard to attract relatively lower interest accounts to maximize profit.

After losing a staggering W1.6 trillion on derivatives in the U.S. real estate market, Woori Bank received a semi-public bailout of W1.3 trillion early this year.