Crude dropped $3.92, or 2.7 percent, to settle at $141.37 a barrel. It finished last week at a record $145.27 per barrel.

Analysts said the drop in price could be in response to Iran's softened view regarding its nuclear program. During the weekend Iran's foreign minister said the country would not attack Israel unprovoked and that discussions with Western governments are in a "new environment" regarding Iran's nuclear program.

"That certainly reduced some of the tensions in the Middle East and some of the upward pressures on oil prices," said James Williams, an economist at energy research firm WTRG Economist, told MarketWatch.com.

Gasoline also fell 8.8 cents to $3.483 a gallon. Heating oil dropped 13.6 cents to $3.97 a gallon. Natural gas fell 60 cents to $12.977 per million British thermal units.

At the pump, the average cost for a gallon of unleaded gasoline was $4.108, up slightly from $4.107 on Sunday, the AAA Daily Fuel Gauge Report said.