TOKYO (AP) _ Tokyo share prices rebounded stongly today after a four-day decline, and the dollar closed unchanged against the yen for the second consecutive day.

The 225-stock Nikkei Stock Average gained 521.30 points, or 2.28 percent, in very thin trading, closing at 23,393.30. It had fallen a total of 610.46 points over the four previous trading days.

For the ninth consecutive session, first session volume fell below 200 million shares. Today's 180 million shares matched Tuesday's volume.

Advancing issues outnumbered declines 700 to 233, with 142 unchanged.

Stock traders said the advance was led by abritrage buying, aimed at profiting from price differences between the spot and futures markets. Trade surplus figures released Tuesday and expectations of lower interest rates also encouraged investors, they said.

''The market was basically led by futures arbitrage buying programs,'' said Peter Boyce, a trader at James Capel Pacific.

''It was basically a technical bounce,'' said Tatsuhiko Takahashi, general manager at Kleinwort Benson International Inc.

The market has been dampened recently by a series of financial scandals. In addition, many Japanese are on summer vacation this week.

On Tuesday, the market was hit by news of the arrest of a former credit union branch manager on suspicion of forging deposit certificates to be used as collateral for huge loans.

Meanwhile, the dollar closed at 136.40 yen, unchanged from Monday's and Tuesday's close but slightly below its overnight finish in New York Tuesday of 136.45. It opened at 136.33 yen and stayed in a narrow range of 136.31 yen to 136.43 yen.

Spot trading totaled $2.59 billion, down from Tuesday's $2.97 billion.

Traders were either out of town or awaiting a decision on German interest rates at the Bundesbank meeting Thursday, dealers said.

The market has mostly absorbed expectations that interest rates will go down, said Takashi Harazawa, a trader at Commerzbank A.G.

''People want to wait and see what will happen tomorrow,'' he said.

The price of the benchmark No. 129 10-year Japanese government bonds closed at 99.80 points, up from Tuesday's 99.66-point finish. Their yield fell to 6.435 percent from 6.460 percent.