Japan's monetary base expanded 4.7 percent in July from a year earlier after a 4.4 percent rise in June, posting the 42nd straight monthly rise, the Bank of Japan said Tuesday.

The average daily balance of the monetary base -- cash in circulation plus current-account deposits held at the central bank by financial institutions and Japan Post -- amounted to 108.52 trillion yen for the reporting month, the BOJ said.

The long-running growth in the monetary base reflects the BOJ's quantitative monetary-easing policy adopted in March 2001 to fight deflation.