The Nikkei tumbled to its lowest close in more than two months on Wednesday amid growing concern over the world's economic recovery. The 225-issue Nikkei Stock Average lost 173.36 points, or 1.98 percent, to 8,596.23, the first time since Aug. 3 it has ended below 8,600. The broader Topix index of all First Section issues on the Tokyo Stock Exchange was down 10.84 points, or 1.49 percent, to 716.84. Brokerage firms, miscellaneous products makers and glass makers saw the biggest losses, while only oil distributors bucked the downtrend among the 33 sectors. On the First Section, declining issues outnumbered advancing ones 1,334 to 230, while 101 remained unchanged. Trading volume decreased to 1,593.48 million shares from Tuesday's 1,624.78 million shares.