Crude fell on Monday, marking its first monthly decline since May, as a looming U.S. government shutdown clouded the outlook for demand while tensions over Iran continued to ease.
The U.S. Senate rejected the House's budget bill, making the shutdown of many agencies at midnight much more likely.
U.S. equities and the U.S. dollar also fell, with energy shares posting the steepest losses of the 10 S&P 500 sectors.
"There's a risk-off environment developing with the imminent government shutdown, which is clearly a negative for just about everything, including economic activity," said John Kilduff, partner at Again Capital LLC in New York.
Concerns that Italy might plunge once again into political turmoil eased after a group of senators from the center-right party of Silvio Berlusconi threatened to form a breakaway group unless the former premier backs down on his hard line to bring down the government.
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