* Chip-related shares plunge after Nvidia disappoints
* Earnings of Alps, Shin-Etsu earnings awaited
* Defensive stocks buck the trend and rise
By Ayai Tomisawa
TOKYO, Jan 29 (Reuters) - Japan's Nikkei fell on Tuesday as warnings from U.S. industry bellwethers Caterpillar and Nvidia dragged down shares of construction machinery makers and chip-related companies.
The Nikkei share average .N225 declined 1.0 percent to 20,448.47 at the midday break.
Japanese machinery .IMCHN.T and electric machinery .IELEC.T sectors were the worst performers on the board, falling 2.6 percent and 2.2 percent, respectively.
Caterpillar Inc (NYSE:CAT) CAT.N on Monday missed quarterly earnings estimates, hurt by soft Chinese demand, higher manufacturing and freight costs. Corp NVDA.O 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. Ltd 6301.T and Hitachi Construction Machinery 6305.T both plunged more than 5 percent.
"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 (NYSE:JPM) 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 8035.T shed 3.8 percent and Advantest Corp 6857.T tumbled 7 percent and Screen Holdings 7735.T dropped 7.6 percent.
Silicon products maker Sumco Corp 3436.T stumbled 5.3 percent and Shin-Etsu Chemical 4063.T lost 2.5 percent.
Bucking Tuesday's trend, defensive stocks such as utility, food and railway names shined. Tokyo Electric Power Co 9501.T rose 2.2 percent, Nissin Foods Holdings 2897.T gained 0.9 percent and Central Japan Railway 9022.T added 0.7 percent.
The broader Topix .TOPX dropped 0.7 percent to 1,544.14. Declining issues outnumbered advancing ones 1,440 to 603.
Alps Alpine Co 6770.T , Shin-Etsu Chemical 4063.T are due to report their quarterly earnings on Tuesday, while TDK Corp 6762.T and Canon Inc 7751.T are slated for Wednesday. (Editing by Richard Borsuk)