Deutsche Securities said on Tuesday that it had placed an erroneous order in Nikkei stock futures shortly and Nikkei 225 mini futures after the opening due to a systems problem within the company.
The order was soon reversed, it said.
"We cancelled the orders when we discovered the glitch one or two minutes after the orders were made," a public relations official from Deutsche said to the Nikkei.
The Nikkei stock average futures contract for June saw 6,900 sell orders of 180 lots each, the Nikkei reported on its Web site, which led the Nikkei average to tumble briefly by more than 100 points to a low of 9,658.44 in early trade.
The index closed 0.6 percent lower at 9,711.83.