Core private-sector machinery orders increased for the third straight month in December, the government said Thursday, strengthening optimism that the economy could bounce back with an upturn in corporate profits and prompting more companies to boost investment.

The orders, which exclude those for ships and from utilities because of their volatility, grew a seasonally adjusted 2.8 percent from November to ¥752.9 billion as higher stock prices and the weaker yen improved business sentiment, the Cabinet Office said.

The government raised its basic assessment of machinery orders, a leading indicator for capital spending by companies, for the first time in 10 months, saying they are "showing signs of moderately picking up."