The Saudi index fell for the fourth consecutive day, as weaker oil prices lowered risk appetite in the region.
As diplomatic attempts to resolve the violence in Ukraine increased and markets braced for a hike in US interest rates, oil prices fell as much as four dollars a barrel on Wednesday, extending a week-long decline.
Brent crude futures slid $ 3.81, or 3.4 percent, to $ 108.86 a barrel in late trade today at 07:41 GMT.
In anticipation of progress in the Russia-Ukraine peace talks, most global stock markets rose and oil prices fell, while bond markets braced for interest rate hikes in the US and UK this week.
After both sides showed progress, Ukrainian and Russian negotiators will meet again via video link today.
The Saudi index dropped 0.4 percent, with Saudi Aramco’s stock falling over 1%.
Aramco’s stock has risen more than 10% so far this year, as crude prices have risen for days following Moscow’s invasion of its neighbor.
The Russian incursion, dubbed a “special operation” by Moscow, has wreaked havoc on global energy markets.