The 225-stock Nikkei, responding to the rout on Wall Street and Europe the previous day, dropped below the 10,000 mark briefly after opening, but then recovered somewhat.

In early trading Tuesday, the index was down about 325 points, or 3.1 percent, to about 10,148. On Monday, the Nikkei gave up more than 465 points, or 4.25 percent, to close at 10,473.09, its lowest closing since February 2004.

Traders blamed the decline on continuing investor concerns about the slowing global economy and a rising yen against the U.S. dollar and euro, Kyodo news service reported.

Hong Kong's Hang Seng Index had plunged nearly 879 points, or 4.97 percent, to about 16,804 in early trading Tuesday.

Markets in Australia and South Korea also were down sharply after opening Tuesday.