Tokyo's Nikkei share average fell for a second day to close 0.73 percent lower on Tuesday, with small investors rushing to sell as the outlook for global markets worsened on growing uncertainty over oil prices and security.
Despite Wall Street's gains a day after a raised security alert level in the United States, big Japanese exporters such as Canon Inc and Toyota Motor Corp extended the previous day's declines.
The Nikkei closed 81.67 points down at 11,140.57, adding to the previous day's 0.91 percent fall. The broader TOPIX index slid 0.76 percent to 1,127.03.
The Nikkei's close was still 4.35 percent above its level at the beginning of this year.
But individual investors who have bought on margin have been squeezed as the Nikkei has turned lower in the past month.
Trading edged higher with 1.098 billion shares changing hands on the Tokyo bourse's first section, the biggest daily total since July 16. Decliners outnumbered gainers 1,070 to 369.
A fall in blue chip shares, prompted partly by broad-based selling by institutional investors, triggered selling in the broader market.
The Nikkei Jasdaq average, which covers all the stocks listed on the Jasdaq market for start-ups, fell 1.72 percent to 1,858.52, its lowest close since May 20.
In early July, the average flirted with four-year highs above 2,050.
Among blue chip exporters, Japan's biggest office machine maker, Canon, which generates about three quarters of its sales overseas, fell 0.55 percent to 5,390 yen, adding to Monday's 0.37 percent loss.
Toyota, Japan's biggest auto maker, skidded 1.35 percent to 4,370 yen. After the market closed, Toyota posted a 32 percent jump in first-quarter operating profit as strong sales overseas helped it offset losses from a weak dollar.
Investors showed a muted reaction to Tuesday's news that the Japanese government would begin an investigation that could lead to duties on imports of DRAM chips made by South Korea's Hynix Semiconductor Inc.
"Given the worsening sentiment towards the technology sector, the market was more focused on bearish factors, such as Olympus' earnings," said Hiroaki Kuramochi, managing director at Bear Stearns in Tokyo.
Digital camera maker Olympus Corp led its rivals lower after the company posted a steep fall in quarterly profits on Monday due to sliding prices of digital cameras.
Olympus, the world's third-best-selling digital camera brand after Sony Corp and Canon, dropped 3.72 percent to 2,070 yen. Sony slid 1.8 percent to 3,820 yen.
Japan's Camera and Imaging Products Association (CIPA) said on Monday that domestic digital camera shipments fell 12.6 percent in June, the first drop since the industry group began publishing data in 1999.