TOKYO, Oct. 25 (Xinhua) -- Tokyo stocks opened sharply lower Thursday as Wall Street's overnight slide saw investors here in a risk-off mood, with the Nikkei retreating more than 3 percent early on.

As of 9:15 a.m, the 225-issue Nikkei Stock Average plummeted 708.75 points, or 3.21 percent, from Wednesday to 21,382.43.

The broader Topix index of all First Section issues on the Tokyo Stock Exchange, meanwhile, tumbled 46.06 points, or 2.79 percent, at 1,606.01.

All industry categories in the main section retreated into negative territory, with electric appliance, chemical, and glass and ceramics product-linked issues comprising those that declined the most in the opening minutes after the morning bell.