Demand for gold from central banks has been elevated in the last two years as some countries diversify their foreign currency reserves
The decline in July was the biggest since the government transferred $40bn to its wealth fund from the central bank to invest abroad
The central bank said the net foreign assets dropped to SAR1.54tn in April from SAR1.57tn the previous month
The government is looking to its largest-ever debt programme to keep the depletion of reserves limited to SAR120bn