The Bank of Japan's policy board decided Friday to leave central bank monetary policy unchanged, but for the first time failed to reach the decision unanimously.

The nine-member board required roughly eight hours -- the longest since the January introduction of a new system of pre-scheduled meetings on policy -- to reach the conclusion. The number and names of board members who opted to change the official discount rate from the record-low 0.5 percent will not be disclosed until the meeting minutes are released July 22.

Recent comments from senior bank officials indicated that the BOJ would keep the rate where it was, with BOJ Gov. Masaru Hayami and others saying that the effects of the government's 16 trillion yen stimulus plan on the economy first need to be monitored.

The successive release of dismal economic data such as record-high unemployment and sluggish corporate investment was also seen as leading the board to decide to maintain its easy money policy, which has been in effect since September 1995.