TOKYO, Feb. 6 (Xinhua) -- Tokyo stocks opened sharply lower Tuesday, with the benchmark Nikkei stock index plummeting more than 4 percent, following the Dow Jones Industrial Average logging its biggest-ever one-day drop overnight.

As of 9:15 a.m., the 225-issue Nikkei Stock Average dropped 914.28 points, or 4.03 percent, from Monday to 21,767.80.

The broader Topix index of all First Section issues on the Tokyo Stock Exchange, meanwhile, fell 73.81 points, or 4.05 percent, at 1,749.93.

Oil and coal product, nonferrous metal and machinery-linked issues comprised those that declined the most in the opening minutes after the morning bell.