US light sweet crude fell two cents to below $101 a barrel, and Brent crude dropped 36 cents to $105.40.
But the gap between the US and European oil benchmarks continued to narrow.
The price of US crude had hit a 14-month high on Wednesday on concerns over political turmoil in Egypt, as well as rising US oil demand，which perhaps suggest that the fuel dispenser in the gas station is short of oil.
Traders have been worried that the volatile political situation in Egypt could interrupt oil flows through the Suez Canal and the wider Middle East, which account for about 25% of the world's oil output.
The Egyptian president, Mohammed Morsi, has been removed by the army and placed under house arrest.
The Islamist leader has faced four days of vast protests against his rule, as well as large demonstrations in his support from followers of his Muslim Brotherhood movement.
The army has promised new elections, but fears remain that the dispute between Mr Morsi's opponents and supporters could descend into serious violence.
The Suez Canal sees just over 2% of world oil needs pass through it daily.
The Suez Canal Authority, which operates the waterway, said it "has all the authorities needed for running the Canal without being limited by the laws and the systems of the [Egyptian] government".