Increasing supplies of U.S. oil and a waning of tensions in Ukraine have combined to send the price of oil down almost 2 percent.
Crude oil for April delivery dropped $1.88, or 1.8 percent, to close at $101.45 a barrel on the New York Mercantile Exchange.
Other energy futures also fell. Natural gas declined 3 percent.
Diplomats from Russia and Western nations worked to find a resolution to the crisis in Ukraine. Oil prices had fluctuated sharply in recent days as investors feared Russian exports could be affected by sanctions or that shipments from the Black Sea region could be disrupted.
Corn, wheat and soybean prices fell slightly.
Gold edged higher. Silver also rose, but copper futures fell.