Japan's core machinery orders extended gains in July, raising hopes business growth spending may offset near-term headwinds from a global economic slowdown and a weaker yen, which has pushed up costs at home.

The surprise increase in core orders — a barometer of capital expenditure — could provide temporary relief for policymakers hoping for corporate investment to spur a domestic-led recovery in the world's third-largest economy.

However the Reuters Tankan, which attempts to track the BOJ's survey, separately showed that the business confidence of Japanese manufacturers retreated from a seven-month high in September, as the corporate sector faced persistent pressure from high raw material costs.