* Nikkei ends down 0.31 pct
* Drop by Wall St shares, stronger yen weigh on market
* Tech shares hit after slide by US chip maker Micron
* Fast Retailing slips on sluggish June Uniqlo sales
By Shinichi Saoshiro
TOKYO, July 4 (Reuters) - Japan's Nikkei fell for a third straight day on Wednesday, as a slide for U.S. chip makers hit technology shares and sluggish sales pulled down index heavyweight Fast Retailing.
The Nikkei share average ended the day down 0.31 percent at 21,717.04 after dropping as low as 21,604.18.
High-tech stocks tracked Wall Street peers and fell, acting as a drag on the Nikkei.
Tokyo Electron dropped 4.44 percent, Advantest Corp shed 4.29 percent, SUMCO Corp fell 4.74 percent and Screen Holdings lost 4.18 percent.
On Tuesday, the tech-heavy Nasdaq fell 0.86 percent, with chip makers sliding after Micron Technology Inc sank when a Chinese court temporarily barred it from selling 26 chip products in the mainland.
Separately, the U.S. government moved to block China Mobile from offering services to the country's telecommunications market on Tuesday, keeping trade tensions on the boil ahead of July 6 when Washington is set to impose tariffs on $34 billion worth of Chinese imports.
"Overnight losses by U.S. shares and a stronger yen is weighing on the market, with some participants opting to close out their positions amid the ongoing trade concerns," said Yutaka Miura, senior technical analyst at Mizuho Securities in Tokyo.
"July 6 is key day of sorts, but the trade spat will remain a market theme as tensions are unlikely to go away before the U.S. midterm elections (in November)."
Fast Retailing retreated 2.15 percent after same-store sales at its Uniqlo clothing outlets in Japan fell 4 percent in June from a year earlier, with a cold, wet spell reducing demand for summer outfits.
But the unseasonably wet conditions boded well for retail shoe store operator ABC-Mart, which rose 1.86 percent after its June same-store sales rose 5.3 percent on brisk sales of waterproof footwear.
Panasonic Corp dropped 1.85 percent after Tesla Inc tumbled overnight on the back of scepticism over its Model 3 vehicles. Panasonic supplies Tesla with automotive batteries.
Of Tokyo's 33 sub-indexes, 16 were in the red, led by electric machinery. Oil and coal products led the gainers following a rise in crude oil prices.
The broader Topix inched up 0.03 percent to 1,693.25. (Editing by Richard Borsuk)