Tokyo  - Tokyo stocks rose upon opening Thursday after the Federal Reserve said it would buy more than 1 trillion dollars in bonds, but they ended the morning session lower as the US central bank's move caused the dollar to fall against the yen, hitting exporters' shares.

The benchmark Nikkei 225 Stock Average temporarily rose above 8,000 before falling 49.28 points, or 0.62 per cent, to 7,922.89.

The broader Topix index of all first-section issues also dropped 0.9 points, or 0.12 per cent, to 763.77.

The falls broke a four-day winning streak in Tokyo and followed Wednesday's aggressive move by the Federal Reserve to keep the US financial sector afloat by buying up government bonds and mortgage-backed securities.

Major US stock indices closed more than 1 per cent higher on the announcement, designed to revive bank lending and end the world's worst financial crisis since the Great Depression.

However, as a result, the dollar plunged against other currencies, including the yen, which makes Japanese products more expensive in their largest overseas market, causing exporters' stocks to drop.

On currency markets at 9 am (0000 GMT), the dollar traded substantially lower at 96.37-42 yen, compared with Wednesday's 5 pm quote of 98.54-55 yen.

The euro traded at 1.3482-87 dollars, up strongly from late Wednesday's quote of 1.3010-12 dollars, and at 129.95-130.00 yen, up from 128.20-24 yen. (dpa)