TOKYO — Asian stock markets were mixed in early trading Thursday in lackluster trade amid uncertainty over the size of the Federal Reserve's bond-buying program aimed at stimulating the U.S. economy.

Japan's benchmark Nikkei 225 stock index fell 5.89 points, or 0.1 percent, to 9,381.14. Investors also stayed on the sidelines, awaiting the outcome of the Bank of Japan's one-day policy board meeting Thursday.

South Korea's Kospi edged up just 0.2 percent to 1,912.41. Australia's S&P/ASX 200 was up 0.8 percent at 4,759.50. Shares in Singapore declined in early trading.

Investors turned jittery ahead of the U.S. midterms elections and the Fed's policy meeting, both set for early next week.

Sentiment turned downbeat following a report in the Wall Street Journal on Wednesday that the size of the Fed's bond purchase may amount to a few hundred billion dollars, falling short of the $500 billion to $1 trillion previously estimated in the market.

The bond purchase would be aimed at driving interest rates lower and encourage lending and spending in a bid to spur the economy.

The Fed will meet next week and details of any stimulus are expected to be announced when the meeting wraps up Nov. 3.

In New York overnight, the Dow Jones industrial average lost 43.18 points, or 0.4 percent, to 11,1126.28 on Wednesday on concerns over the Fed's stimulus measures. (AP)