TOKYO, July 22 (Xinhua) -- Japan's key stock index extended drops on Tuesday as domestic political uncertainty and trade concerns weigh on investor sentiment.
The benchmark Nikkei stock index, the 225-issue Nikkei Stock Average, closed at 39,774.92, down 44.19 points or 0.11 percent, from the previous trading day.
While early gains were supported by a strong performance in U.S. tech stocks overnight and a relief rally following Japan's upper house election, the Nikkei briefly surpassed the psychological 40,000 mark before retreating in the afternoon.
Persistent selling by pension funds and individual investors looking to take profits dragged the index lower, amid ongoing concerns over Japan's domestic political instability and the uncertain outcome of U.S.-Japan tariff negotiations.
The broader Topix index edged up 1.71 points, or 0.06 percent, to close at 2,836.19.
Of the listed stocks on the Tokyo Prime Market, 687 rose, while 877 declined and 60 were flat. ■
