TOKYO -- Confidence among Japanese manufacturers hit a near three-year low in the final months of 2012, a Bank of Japan (BoJ) survey showed Friday, adding to concerns about the already weak economy.

The central bank's quarterly Tankan survey came just days after official figures showed the world's third-largest economy shrank in the July-September period, buffeted by a weak global outlook, a strong yen and a spat with China.

It also comes ahead of national polls Sunday that are expected to see Prime Minister Yoshihiko Noda ousted in favor of Shinzo Abe, who has promised to press more aggressively for a looser monetary policy.

The worst Tankan results since the start of 2010 would likely heap pressure on Japan's central bankers to step up their economic offensive at a policy meeting next week, analysts said.

"Pressure on the Bank of Japan for more monetary easing will inevitably increase," said Tsuyoshi Ueno, senior economist at NLI Research Institute in Tokyo.

"The survey showed manufacturers are seriously concerned about the economy."

Sentiment among large manufacturers, including automakers and technology firms, plunged to minus 12 from minus three in the third quarter. Economists had expected a reading of minus 10.

The survey of over 10,000 firms shows the percentage of companies saying business conditions are good minus those saying they are bad and are a key measure used by the BoJ in formulating monetary policy.

"The survey suggested that there remains the risk that the expected economic recovery the BoJ assumes could come even later than the central bank is currently envisaging," said Yoshiro Sato, an economist at Credit Agricole.

Also Friday, revised official data showed that Japan's factory output rose 1.6% in October, slightly down from a preliminary 1.8% expansion.

The uptick in industrial production data had marked a glimmer of hope among a batch of otherwise gloomy economic figures.