South Korean shares ended in negative territory Monday as local institutions reduced their holding of stocks ahead of a full-scale announcement of the first quarter earnings results from this week. The benchmark Korea Composite Stock Price Index (KOSPI) slid 5. 06 points, or 0.25 percent, to close at 1,999.22. Trading volume stood at 201.22 million shares worth 2.2 trillion won (2.12 billion U.S. dollars). Institutional investors sold a net 120.3 billion won worth of stocks as they turned cautious as big corporations are set to unveil their first quarter earnings. Top automaker Hyundai Motor is scheduled to unveil its earnings for the first quarter Wednesday, and consumer electronics giant LG Electronics and market bellwether Samsung Electronics will show their first quarter earnings next week. Hyundai shares dipped 0.4 percent, and its affiliate Kia Motors declined 0.8 percent. The nation's No.1 auto parts maker Hyundai Mobis lost 0.5 percent, and top mobile operator SK Telecom fell 0. 2 percent. Samsung shares, which account for more than 20 percent of the total market capitalization, edged up 0.1 percent as its preliminary figure for the first quarter earnings were roughly in line with market expectations. Memory chip giant SK Hynix added 0.5 percent, and the nation's biggest web search engine NAVER climbed 0.9 percent. Leading chemical firm LG Chem gained 2.2 percent. Foreign and retail investors bought shares worth 75.5 billion won and 49.2 billion won respectively, limiting the KOSPI's further decline. The South Korean currency finished at 1,039.0 won against the greenback, down 1.6 won from Friday's close. Bond prices ended mixed. The yield on the liquid three-year treasury notes closed unchanged at 2.88 percent, but the return on the benchmark 10-year government bonds rose 0.02 percentage point to 3.56 percent.