TOKYO, March 20 (Reuters) - Japan's Nikkei share average fell on Tuesday morning as local tech stocks tracked their U.S. counterparts' declines on Wall Street, which knocked other sectors into negative territory.
The Nikkei dropped 0.9 percent to 21,294.61 in midmorning trade.
Concerns about increased regulation of large tech companies hit U.S. tech stocks as Facebook came under fire following reports it allowed improper access to user data. Japanese tech shares followed this trend in the Asian day.
Semiconductor equipment makers tumbled, with Tokyo Electron sliding 1.8 percent, Advantest Corp shedding 1.4 percent and electrical equipment maker Yaskawa Electric Corp tumbling 3.0 percent.
However, traders said that downside should be limited thanks to the Bank Of Japan's buying of exchange-traded funds to support the market. The central bank bought 73.5 billion yen of ETFs on Monday.
With Japanese markets closed for a national holiday on Wednesday, investors are expected to refrain from taking large positions on Tuesday, they added.
Of Topix's 33 subsectors, 24 were in negative territory. Mining stocks underperformed after oil prices slipped, with Inpex Corp weakening 1.9 percent.
The broader Topix dropped 0.7 percent to 1,707.31.
Reporting by Ayai Tomisawa; Editing by Sam Holmes