South Korean refining shares advanced in early trading, with GS and S-Oil benefiting from higher crude prices, resilient refining margins and expectations for stronger earnings. GS rose 5.64% to 103,000 won by 9:38 a.m. on the 12th after touching 106,400 won, while S-Oil gained 4.10% to 147,400 won and reached 151,900 won intraday. Oil prices extended gains as uncertainty around U.S.-Iran talks over the Strait of Hormuz, a key global shipping chokepoint, reinforced concerns about supply. Brent crude for October delivery settled 1.4% higher at $88.91 a barrel and West Texas Intermediate for September rose 1.3% to $83.20. Brokerages also highlighted tight petroleum product supply in the second half, helped by disruption to Middle East exports and damage to Russian refining facilities. Eugene Investment & Securities projected S-Oil's third-quarter operating profit at 1.1 trillion won, up 367% from a year earlier, while BNK Investment & Securities said GS's second-quarter consolidated operating profit beat market expectations by 53.3%, with GS Caltex contributing 930 billion won.