* Komatsu gains after Caterpillar's profits
* Insurers, banks in demand after U.S. yields rise
* Declining shares outweigh advancing ones
By Ayai Tomisawa
TOKYO, Oct 25 (Reuters) - Japan's Nikkei share average dropped for the first time in 17 days in choppy trade on Wednesday as investors took profits on the record run of consecutive daily gains, although higher U.S. yields supported financial stocks.
The Japanese market posted an unprecedented 16 straight days of gains, helped this week by the victory of Prime Minister Shinzo Abe's coalition in Sunday's election, which raised the prospect of continued stimulus.
The Nikkei ended 0.5 percent lower at 21,707.62. It opened 0.4 percent higher and traded in positive territory in the morning, but languished in the afternoon as investors grew cautious about the rally.
Over the past 16 days, it gained 7.1 percent.
On Wednesday, declining issues outweighed advancing ones by 67 percent to 28 percent.
"There have been fears against profit-taking after posting a record rally. People were testing the water, and once some started to sell, others followed suit," said Yutaka Miura, a senior technical analyst at Mizuho Securities.
Exporters were weak, with Fanuc falling 1.1 percent, Tokyo Electron dropping 0.9 percent and Mitsubishi Motor shedding 1.6 percent.
Insurers and banks attracted buyers after U.S. benchmark 10-year Treasury note yields rose to their highest in more than five months on Tuesday.
Dai-ichi Life Holdings rising 0.8 percent, Sompo Holdings gaining 1.3 percent and Mitsubishi UFJ Financial Group surging 1.8 percent.
Construction equipment makers Komatsu Ltd soared 3.3 percent and 0.8 percent, respectively after Caterpillar Inc blew past Wall Street's profit and revenue estimates for the third quarter.
The broader Topix shed 0.3 percent to 1,751.43. (Editing by Sam Holmes)