On the New York Mercantile Exchange, West Texas Intermediate crude oil gave up $1.68 and costs $99.13 per barrel. Reformulated blendstock gasoline prices shed 1.77 cents to $2.6555 per gallon. Home heating oil shed 2.02 cents to $3.0152 per gallon. Natural gas was off 10 cents to $3.67 per million British thermal units.
At the pump, the national average price of unleaded gasoline dropped to $3.349 per gallon from Sunday's $3.353, AAA's Daily Fuel Gauge Report said.
Crude had been more than $100 per barrel since July and spiked to more than $110 in early September after U.S. President Barack Obama threatened a military strike against Syria in response to its alleged use of chemical weapons against civilians in the country's continuing civil war.
As that threat receded, oil prices retreated as well.
Abdalla Salem el-Badri, the general secretary of the Organization of Petroleum Exporting Countries, said the world is well-supplied. In step with that assessment, Japan recently reported that crude oil imports in September dropped 19 percent, the largest decline in 11 months.