RIYADH: Saudi Arabia’s main index ended the last trading session of the week lower as investors kept a keen eye on the unstable oil prices this week. The Tadawul All Share Index slipped 0.11 percent to end Thursday at 11,757, while the parallel market Nomu finished almost flat at 20,223. In the energy sector, Brent crude reached $93.22 per barrel, while WTI crude traded at