Money supply in South Korea kept rising in September amid the protracted trend of low interest rate, central bank data showed Tuesday.

The M2, called broad money, grew 6.4 percent in September from a year earlier, after rising 6.7 percent in the prior month, according to the Bank of Korea (BOK).

The continued growth came as demand for debts from households and companies remained strong amid the near-record-low policy rate.

The BOK refrained from altering its benchmark rate since the bank raised it to the current 1.50 percent from an all-time low of 1.25 percent in November last year.

The M1, dubbed narrow money, increased 4.3 percent in September from a year earlier.

The M1 refers to currency in circulation, demand deposits and transferable savings deposits equivalent to cash. The M2 adds money market funds, time deposits and financial products that mature in less than two years to M1.

Liquidity of financial institutions, called Lf, expanded 7.2 percent in the cited period. The year-over-year expansion of liquidity aggregate, the broadest measure of money supply, was 6.2 percent.

The Lf includes financial products with a maturity of more than two years and liquidity at insurers and brokerages along with M2. The liquidity aggregate adds state and corporate bonds to the Lf.