* Nikkei ends up 0.08 pct after brushing 12-day low
* Defensive stocks sought amid souring of broader sentiment
* Chip-related shares retreat after Nvidia disappoints
By Ayai Tomisawa and Shinichi Saoshiro
TOKYO, Jan 29 (Reuters) - Japan's Nikkei inched up on Tuesday, led by gains in defensive shares such as utilities, after the index spent much of the day in the red after warnings from U.S. industry bellwethers Caterpillar and Nvidia raised concerns over weakening Chinese demand.
The Nikkei share average ended the day up 0.08 percent at 20,664.64 after going as low as 20,406.22, its weakest since Jan. 17.
Reflecting the cautious mood, gains were made by defensive shares such as utilities, food and railway operators.
Tokyo Electric Power Co rose 3.7 percent, Nissin Foods Holdings 1 percent and Central Japan Railway added 1.3 percent.
Of the Tokyo Stock Exchange's (TSE) 33 sub-indexes, machinery and electric machinery sectors were some the worst performers, shedding 1.6 percent and 1.2 percent, respectively.
Caterpillar Inc on Monday missed quarterly earnings estimates, hurt by soft Chinese demand, higher manufacturing and freight costs.
Nvidia Corp cut its fourth-quarter revenue estimate by half a billion dollars because of weak demand for its gaming chips in China and lower-than-expected data centre sales.
Komatsu Ltd and Hitachi Construction Machinery both lost more than 4 percent following Caterpillar's results.
"We expected that slowing China demand would hit global manufacturers' earnings to some extent but their missing their estimates was shocking," said Yoshinori Shigemi, global market strategist at JPMorgan Asset Management.
The downbeat results from the U.S. manufacturers point to troubles for Japanese machinery makers already struggling with declining orders from China, he said.
"The market is cautious against earnings of manufacturers which have large exposure to China," Shigemi said.
Chip-related stocks also lost ground after Nvidia's estimate cut.
Tokyo Electron shed 2.4 percent, Advantest Corp slid 4.6 percent and Screen Holdings dropped 7.6 percent.
Silicon products maker Sumco Corp stumbled 5.3 percent and Shin-Etsu Chemical lost 6 percent.
Gainers included electronic devices and precision mouldings maker Shin-Etsu Polymer Co, which advanced 4.8 percent after its operating profit for the nine months through December 2018 rose 19.2 percent to 6.78 billion yen ($62 million).
The broader Topix rose 0.1 percent to 1,557.09.
$1 = 109.3000 yen Editing by Simon Cameron-Moore