New York's main contract, light sweet crude for February delivery, dropped 50 cents to $91.05 a barrel and Brent North Sea crude for March delivery was up 21 cents at $97.64.
"The Shanghai Exchange slumped three percent (on Monday), which prompted profit-taking in oil," said Ong Yi Ling, investment analyst for Phillip Futures in Singapore.
Shanghai's Composite Index closed Monday down 3.03 percent, or 84.68 points, at 2,706.66 amid growing expectations that China will roll out tougher measures to crack down on inflation, including another interest rate hike.
Optimism about the global economic recovery and interest from bullish investors have pushed crude prices close to $100 a barrel in recent sessions.
The rise in crude has also been attributed to a harsh winter hitting Europe and parts of North America, as well as growth in China and other developing nations.
The OPEC oil cartel, which pumps 40 percent of world crude, revised upwards its 2011 world demand growth estimate on Monday, given the pace of global economic recovery and cold winter weather in the northern hemisphere.
The Organisation of the Petroleum Exporting Countries (OPEC) said it was pencilling in world oil demand growth of 1.23 million barrels per day to 87.32 million for this year, a 1.43 percent jump compared with 1.37 percent previously forecast.
"The magnitude and the speed of the world economic recovery will have a remarkable impact on world oil demand this year," OPEC said in its latest monthly bulletin.