Japan's Nikkei average was down three percent by midafternoon on Friday as investors dumped techs and other blue chips that had powered the market's recent rally on worries that the gains had been overdone.
Tech issues including Toshiba Corp, Japan's largest chip maker, extended recent falls after disappointing results from Internet company Yahoo Inc and lackluster U.S. jobs data pushed the Nasdaq down 1.81 percent on Thursday.

"A large part of the recent rally has been driven by foreign investors playing catch-up, not necessarily any great improvement in Japan's economic fundamentals," said Kazunori Ohtomo, senior fund manager at STB Asset Management.

"In particular the sharp rise in tech stocks was not sustainable. It's natural that we're correcting downwards."

The Nikkei was down 308.17 points or 3.05 percent at 9,652.45 as of 0445 GMT, while the broader TOPIX index lost 2.69 percent to 947.90.

Toshiba was down 5.8 percent at 471 yen after marking a 13-month high of 541 yen on Tuesday.

Internet service provider Softbank, the most active issue by value, tumbled 10.62 percent to 2,905 yen, adding to its 10 percent dive in the previous session.

The shares of the once high-flying Internet investor had more than doubled in an 11-day winning streak until Wednesday.

Toyota Motor Corp slumped 5.23 percent to 3,260 yen after Nikko Citigroup cut its rating on Japan's largest auto maker to "in-line, high risk" from "outperform, high risk."

The brokerage said in a report it expected a double digit fall in Toyota's first-quarter profit compared to the year earlier, due to a rise in the yen against the dollar. Toyota will announce results for the April-June quarter on August 5.