Oil prices closed down on Monday, as investors took profit from the near-record highs of last week and weighed the threat of a deeper economic slowdown in the United States, the world's top oil consumer.
U.S. light, sweet crude fell $1.42 to end trade at $80.24 per barrel.
London Brent crude dropped $2.01 to $77.16.
"Today's drop in crude futures is a follow-through from Friday's end-of-the-quarter profit-taking," said Phil Flynn of Alaron Trading.
Oil prices have surged more than 30 percent this year, to an all-time high of $83.90 in late September, on expectations of a supply shortfall in the fourth quarter as heating demand peaks in the Northern Hemisphere.
But traders, eyeing a credit crunch in the United States and Europe that is showing signs of slowing economic growth, have pushed down the price to take profits.