Riyadh-based Tadawul All Share Index (Tasi) stabilised Tuesday, closing 0.01% higher at 6,396.41 points. Advances in the petrochemical sector prevented the market from falling further, as most segments ended in the red. Yanbu National Petrochemical Co. (Yansab) gained 3.85% to close at SR40.50 and shares of National Petrochemical Co. surged three percent to close at SR18.75.