Share prices plunged again in morning trading today on the Tokyo Stock Exchange.
The 225-issue Nikkei stock average fell 317.16 points, or 1.6%, closing the morning session at 19,599.96.
The dip followed a small rally Tuesday, when the Nikkei gained 80.47 points.
Monday, the index fell 618.90 points to 19,837.16, sliding below the critical 20,000 mark to its lowest close in more than five years.
Early today, traders said corporate investors continued to sell stocks to settle accounts by the end of Japan's fiscal year amid pessimism about the economy.
Many of Japan's major companies, including automobile, steel, electronics and industrial machinery makers, forecast declines in their corporate earnings in the fiscal year ending March 31.
"It's been a one-sided slide from the morning," said Kunihiko Hitomi, an analyst with Wako Securities. "The bottom is still nowhere in sight."
With the psychologically important 20,000-point level broken, some analysts say the average's true value is only 17,000 to 18,000 points.
At a news conference, Minoru Nagaoka, the president of the Tokyo Stock Exchange, demanded that the government swiftly enact measures to buoy the sagging stock market.
Meanwhile, a Tokyo Stock Exchange official said the exchange is expected to post a $70.2-million loss in the fiscal year, largely because of sharp declines in volume the past 12 months.
Daily volume in recent months has averaged just above 200 million shares, about one-tenth of peak-day volume in the boom days of the late 1980s.