South Korean shares fell in choppy trading on Friday as investors took to the sidelines ahead of the Upper House election in Japan on Sunday that was expected to strengthen the weak yen trend. The benchmark Korea Composite Stock Price Index (KOSPI) fell 4. 07 points, or 0.22 percent, to close at 1,871.41. Trading volume stood at 315.47 million shares worth 3.55 trillion won (3.17 billion U.S.dollars). The key index fluctuated in a narrow range throughout the session before ending eventually in negative territory as investors were reluctant to take aggressive positions ahead of the Sunday election in Japan. The ruling Liberal Democratic Party (LDP) and its partner New Komei Party were widely forecast to win a landslide victory at the House of Councilors election this weekend, boosting concerns that the monetary easing-dependent growth policies would maintain the depreciation of the yen to the dollar. The weak yen trend was feared to damage price competitiveness of South Korean exporters that are competing with Japanese rivals in overseas markets. Cautiousness remained among investors over the second-quarter earnings season that will be launched from next week. Foreign investors kept their selling streak for two straight sessions by offloading a net 130.8 billion won worth of local shares. Institutional and retail investors bought stocks worth 92.4 billion won and 25 billion won each. Among large-cap shares, decliners outnumbered gainers. Market bellwether Samsung Electronics slid 1.5 percent and top steelmaker POSCO fell 0.6 percent. Memory chip giant SK Hynix retreated 2.7 percent, and the nation\'s biggest mobile operator SK Telecom lost 1.6 percent. Top automaker Hyundai Motor gained 0.2 percent, but its affiliate Kia Motors dipped 0.2 percent. The nation\'s No.1 auto parts maker Hyundai Mobis rose 1.4 percent. The local currency finished at 1, 121.7 won against the greenback, up 4.6 won from Thursday\'s close. Bond prices ended mixed. The yield on the liquid three-year treasury notes closed steady at 2.85 percent, but the return on the benchmark 10-year government bonds added 0.01 percentage point to 3.42 percent.