Core private-sector machinery orders fell a seasonally adjusted 13.2 percent in September from the month before to 879 billion yen, the Cabinet Office said Thursday.
The decline follows an 8.7 percent rise in August that was the first gain in four months.
A Cabinet Office official said it is unclear whether the drop in orders -- an unadjusted 11.8 percent down from a year before -- was due to the Sept. 11 terrorist attacks in the United States.