Core machinery orders from Japanese businesses shriveled a seasonally adjusted 11.8 percent in January from the previous month to 966.9 billion yen after a 3.8 percent rise in December, the government said Thursday.

The downturn was the largest since the 16.5 percent contraction in September and forced the Cabinet Office to downgrade its assessment of machinery orders.

"Machinery orders hang in the balance at the moment, so we have decided to lower our evaluation of them for the first time in five months," an official said. "We need to monitor machinery order moves closely."