Japan's key money supply gauge expanded a stronger than expected 2.1 percent in February from a year earlier on growth in the balance of time deposits at a time of crisis, the Bank of Japan said Monday.

The average daily balance of M2 came to ¥743.1 trillion. The headline reading followed an upwardly revised 2.0 percent growth in January and was above the average market forecast of a 1.9 percent increase in a Kyodo News survey.

M3, a wider gauge, was up 1.1 percent to ¥1.042 quadrillion, logging the sharpest gain since November 2004 on a slower decline in postal savings, the central bank said in a preliminary report.

M2 consists of cash in circulation, demand and time deposits, and certificates of deposit at domestic banks, including the BOJ and Japanese branches of foreign banks. M3 includes cash in circulation, demand and time deposits and CDs at all depository institutions, including Japan Post Bank.

Growth in the balance of quasi-money, which includes risk-free, higher-interest time deposits, remained strong. It rose 2.5 percent to ¥540.2 trillion in February. The pace of increase matched the January result and was the fastest in nearly 10 years.

It appears the trend for investors to put their money into time deposits, spurning stocks and other risky assets amid the global financial turmoil, is continuing, the BOJ said.

M1, which refers to cash in circulation and demand deposits, dropped 0.4 percent to ¥477.9 trillion.