South Korea's money supply grew at a slower pace in January than in the previous month as banks remained wary of extending loans, the central bank said Wednesday. South Korea's M2, a narrow measure of money supply, rose 5.2 percent to 1,937 trillion won (US$1.81 trillion) in January from a year earlier, compared with a 5.3 percent on-year gain in December, according to the Bank of Korea (BOK).