Japan's core private-sector machinery orders dropped in September from a month earlier, the government said in a report on Thursday.

According to the Cabinet Office, the orders, excluding those for ships and utilities because of their volatility, fell 18.3 percent in September from the previous month.

The orders totaled 802.2 billion yen (7.1 billion U.S. dollars) in the recording month, the government's data showed.

The decline in core orders in the recording period comes on the heels of a 6.8-percent increase booked a month earlier.

Machinery orders are a key advance indicator for corporate capital spending and the government uses the data to predict the strength of business spending in a six to nine month period ahead.

A drop in capital expenditure here can dent the economy as Japanese companies are producing less machinery to meet slowing demands from overseas markets.

Such business investment, however, accounts for roughly 15 percent of Japan's gross domestic product.

Types of machinery included in the monthly government survey comprise engines and turbines, heavy electrical machinery, electronic and communication equipment, industrial machinery, machine tools, railway rolling stock, road vehicles, aircraft, ships, water crafts, as well as sub types in those categories.