Investors are worried about the outlook for crude oil demand, which offsets the positive impact of easing international tensions. Crude oil futures prices fell slightly from the nearly one month high reached last week, ending four consecutive days of gains.

WTI futures for December delivery on the New York Mercantile Exchange fell 85 cents to $55.81 a barrel, or 1.5%. Last Friday, the contract hit its highest closing price since September 24, while in the overall trading last week, WTI futures rose 5.2% on a monthly basis. Meanwhile, the price of Brent crude oil for December delivery on ice Europe futures exchange in London also fell 45 cents, or 0.7%, to US $61.57 per barrel, after the contract hit its highest closing price since September 26 on Friday and rose 4.4% in overall trading last week.