South Korean shares fell for two straight sessions on Wednesday as local institutions sold stocks amid concerns over Spain where demonstration against the new round of austerity measures intensified. The benchmark Korea Composite Stock Price Index (KOSPI) retreated 10.97 points, or 0.55 percent, to close at 1,980.44. Trading volume stood at 1.19 billion shares worth 4.73 trillion won (4.22 billion U.S. dollars). The KOSPI stayed in negative terrain throughout the session as Wall Street ended bearish after news that thousands of Spanish demonstrators protested in Madrid on Tuesday against the government that was preparing new austerity plan for the 2013 budget to be announced later this week. Worsening market sentiment, the U.S. Federal Reserve Bank of Philadelphia President Charles Plosser said that the newly announced mortgage bond-buying program, known as QE3, will have little impact on boosting economic growth or lowering unemployment. Foreign investors turned into net buyers in the last minutes of trading, purchasing a net 27.9 billion won worth of stocks. Retail investors bought a net 142.1 billion won worth of shares, but institutional investors sold shares worth 171.3 billion won. Program-linked transactions posted net selling worth 194 billion won. Among large-cap shares, decliners outnumbered gainers. Market bellwether Samsung Electronics, which account for around 15 percent of total market capitalization, edged down 0.1 percent to 1,325,000 won. Top steelmaker POSCO declined 1.07 percent to 371, 000 won, and leading chemical firm LG Chem retreated 0.76 percent to 325,000 won. Top automaker Hyundai Motor advanced 1.02 percent to 247,000 won, but its affiliate Kia Motors slid 0.83 percent to 71,900 won. The nation's No.1 auto parts maker Hyundai Mobis retreated 1.25 percent to 316,500 won. The local currency finished at 1,121.1 won against the greenback, down 1.8 won from Tuesday's close. Bond prices ended higher. The yield on the liquid three-year treasury notes lost 0.01 percentage point to 2.79 percent, and the return on the benchmark five-year government bonds slid 0.01 percentage point to 2.87 percent.