U.S. stock exchange officials were investigating whether erroneous trades caused a sudden slump in share prices that wiped nearly $1 trillion off U.S. equity values at the peak of the sell-off before prices clawed back some of their losses.

Fast Retailing fell nearly 6 percent, the top drag on the Nikkei 225, after the company said that same-store sales at its Uniqlo casual-clothing chain fell 12.4 percent in April from a year earlier as cool weather hurt sales of spring items.

"The Greece debt crisis is reminding investors of what happened after Lehman Brothers' collapse. A failure by one financial institution ended up triggering a ripple effect on the global economy," said Kazuhiro Takahashi, general manager at Daiwa Securities Capital Markets.

The benchmark Nikkei fell as much as 4.1 percent at one stage to 10,257.32, its lowest since early March and below the 200-day moving average of around 10,300, before trading down 3.9 percent at 10,283.40.

The broader Topix shed 3.3 percent to 924.73.

Partly because some erroneous trades were suspected to be behind the plunge on Wall Street, the Nikkei will for now likely find support around its 200-day moving average, market players said.

"People were expecting an adjustment anyway but I think most of them thought it would stop around 10,600. The big issue for today is whether it can end above the 200-day moving average or not," said Kenichi Hirano, operating officer at Tachibana Securities.

"When the economy's on a recovery track, as it is right now, it's hard to imagine the Nikkei staying much below the 200-day moving average for long. It just isn't logical."

EXPORTERS DRAG

In the United States Thursday, the S&P 500 dived 9 percent at one stage before ending down 3.2 percent.

The European Central Bank did not discuss the outright purchase of European sovereign debt at a meeting Thursday but instead gave verbal support to Greece's savings plan, disappointing some investors.

A stronger yen was also hurting shares of exporters on worries the stronger currency will curb Japanese exporters' profits when repatriated.

The euro was around 115 yen in early Asia trade, after shedding around 10 yen at one point the previous day.

Digital camera maker Canon lost 4.7 percent to 4,020 yen and chip-tester maker Advantest Corp shed 4.8 percent to 2,227 yen. Kyocera Corp dropped 4.6 percent to 8,680 yen.

Automaker Honda Motor Co skidded 4.1 percent to 2,983 yen.

Fast Retailing sank 5.6 percent to 13,090 yen.

Nintendo Co tumbled 10.7 percent to 27,370 yen after the game console maker forecast a second straight year of smaller profits as sales of its Wii console slow, after posting its first quarterly profit growth in more than a year.

(Editing by Joseph Radford)

Sourced from www.reuters.com