TOKYO (AP) _ Share prices fell moderately in active trading on the Tokyo Stock Exchange Wednesday. The dollar finished higher against the Japanese yen.

The 225-issue Nikkei Stock Average fell 125.83 points, or 0.53 percent, closing at 23,317.78. On Tuesday, the average rose 309.18 points, or 1.34 percent.

The Tokyo Stock Price Index of all issues listed in the first section closed at 1,800.15 points, down 7.56 points, or 0.42 percent.

Volume on the market's first section was estimated at 600 million shares, up from Tuesday's 548 million shares.

The dollar closed at 133.95 yen, up 0.32 yen from Tuesday's close and also above its overnight finish at 133.85 yen in New York. After opening at 133.93 yen, it ranged between 133.86 yen and 134.00 yen.

The Nikkei average posted moderate gains at the close of the morning session before falling back in the afternoon.

Shigeki Sato of Okasan Securities said the Nikkei's early rise was supported by active buying by foreign investors and arbitrage trading.

But he said no specific news was moving the market as a whole.

Other traders said that despite an overnight decline on Wall Street and the yen's slip against the dollar, stock trading remained substantial, with volume on the first section totaling 300 million shares in the morning session alone.

The dollar started to slip after an initial boost of buying to cover short positions but later inched back and just surpassed its opening level, traders said.

''Dollar trading is static. There are no customers,'' said Tadasu Ochi, a dealer with Mitsubishi Bank.

The dollar has been falling steadily since the U.S. Federal Reserve Board lowered its key lending rate Friday in an attempt to stimulate the economy.

Lower interest rates tend to weaken a nation's currency by making it less attractive to investors.

Most market players do not expect the Fed to further lower interest rates immediately but are still reluctant to buy the dollar, Ochi said.

Benchmark No. 129 10-year Japanese government bonds stood at 101.53 points by midafternoon, down from Tuesday's 101.64-point finish. Their yield rose to 6.125 percent from 6.105 percent.