An electronic board showing the Korea Composite Stock Price Index at a dealing room of the Hana Bank headquarters in Seoul on Friday. (Yonhap) Seoul shares opened lower Friday, tracking overnight losses on Wall Street as US Treasury yields again rose and higher oil prices weighed on investor sentiment.After opening 1.35 percent lower, the benchmark Korea Composite Stock Price Index trimmed its losses, falling 21.05 points, or 0.31 percent, to 6,831.53 as of 9:15 a.m.US Treasury yields resumed their upward trend Thursday, reversing much of the previous day's decline following the US Treasury's announcement of an expanded bond buyback plan.The rebound came as investors grew skeptical that the expanded buybacks would provide more than temporary relief from rising long-term borrowing costs.Overnight, the Dow Jones Industrial Average shed 1.32 percent, while the S&P 500 slipped 0.87 percent. The tech-heavy Nasdaq Composite Index fell 1 percent.Higher oil prices added to the downward pressure on stocks, with Brent crude rising more than 2 percent amid renewed US-Iran tensions.In Seoul, most shares traded lower, while major chipmakers bucked the trend on continued expectations for shareholder returns.Market bellwether Samsung Electronics climbed 0.65 percent, while its chipmaking rival SK hynix rose 1.83 percent, extending its rally after announcing a share buyback program Wednesday.Battery manufacturer LG Energy Solution shed 2.65 percent, and leading automaker Hyundai Motor fell 1.2 percent.The Korean won was trading at 1,391.4 won against the US dollar as of 9:15 a.m., up 4.6 won from the previous stock market session's close. (Yonhap)