Seoul stocks opened lower Tuesday after weaker-than-expected tentative earnings results announced by Samsung Electronics and overnight U.S. stock losses. The benchmark Korea Composite Stock Price Index dropped 0.55 percent, or 14.28 points, to 2,596.10 in the first 15 minutes of trading. Ahead of the trading session, Samsung Electronics estimated its third-quarter operating profit to reach 9.1 trillion won, apparently failing to meet market expectations due to the lukewarm performance of its flagship memory chip business. Overnight, U.S. stocks fell across the board after Treasury yields hit their highest levels since the summer following stronger-than-expected jobs data for September and rising oil prices. The Dow Jones Industrial Average dropped 0.94 percent, the S and P 500 slumped 0.96 percent and the tech-heavy Nasdaq composite also fell 1.18 percent. Semiconductor shares retreated following Samsung's announcement, with the company's shares losing 0.49 percent and industry rival SK hynix also dropp ing 0.49 percent. Bio and automotive shares also fell to negative terrain. Samsung Biologics lost 0.7 percent and Hyundai Motor slipped 0.61 percent. In contrast, defense-related shares continued to rise amid ongoing tensions in the Middle East. Defense equipment manufacturer Hanwha Aerospace rose 1.28 percent. The local currency was trading at 1,344.85 won against the U.S. dollar, up 1.85 won from the previous session. Source: Yonhap News Agency