The Bank of Japan on Friday held off fresh easing measures, opting not to build on last month's boost to its asset-purchase scheme but warned the economy faced risks from a deeper global slowdown.

The BoJ said in a statement its policy board had voted unanimously to keep rates at between zero and 0.1 percent and left an 80 trillion yen (US$1.02 trillion) asset purchase programme in place.

Last month, the BoJ unveiled plans to boost the fund by 10 trillion yen as pressure increased on the central bank to follow similar moves by its European and US counterparts.

However, it left the door open to further measures further down the line as it assesses the impact of its latest move on the stuttering economy.

"Regarding risks, there remains a high degree of uncertainty about the global economy, including the prospects for the European debt problem," the BoJ said.

It was also concerned about, "the momentum toward recovery for the US economy, and the likelihood of emerging and commodity-exporting economies simultaneously achieving price stability and economic growth."

Reiterating concerns over a slowdown at home, the BoJ said: "Exports and industrial production have been relatively weak as overseas economies have moved somewhat deeper into the deceleration phase."

The statement said the bank "recognises that Japan's economy faces the critical challenge of overcoming deflation", adding that it "will proceed with monetary easing in a continuous manner".

Japan's new economy and fiscal policy minister Seiji Maehara, an advocate of more stimulus measures, attended Friday's policy meeting, a move to seen as part of a government move to pressure the bank to take more action.

Maehara, who also serves as a national strategy minister, was the first economy and fiscal policy minister to attend the meeting since Heizo Takenaka in 2003.

Ahead of the meeting, Maehara, who took office on Monday, said he wanted to attend the meeting "based on the government stance of calling for strong easing financial measures to end deflation".

Maehara is eligible to attend BoJ meetings and express his opinions, but has no right to vote on monetary decisions by the independent central bank.

Friday's move comes after closely-watched quarterly BoJ Tankan survey released Monday found sentiment among large manufacturers fell to "minus three" in September from "minus one" in June.

And there were warnings things could get worse, with economists saying any possible impact from Japan's territorial dispute with China was not fully reflected in the survey, as a majority of companies had given answers well ahead of the September 28 deadline.

Japanese businesses have taken a hit from a flare-up between Tokyo and Beijing over the ownership of islands in the East China Sea.

Japan's nationalisation in September of three islands in the chain, called Senkaku in Japan and Diaoyu in China, triggered anti-Japan rallies across China.

Major Japanese companies were forced to close factories temporarily and reports have emerged of demand for Japanese goods being hit.

Analysts said the BoJ's inaction Friday had been expected.

"Hopes for more easing on the heels of the prior BoJ move were slim at best," said Yutaka Miura, senior technical analyst at Mizuho Securities.

"But stocks nevertheless reacted to the renewed rise in the yen, which, while not dramatic, was enough to push the major indexes into the red," Miura told Dow Jones Newswires.

The Nikkei index, which initially fell in response to the announcement, was up 0.35 percent in the afternoon while the yen bought 78.36 yen, compared with 78.45 yen in morning trade.