Oil prices dropped slightly on concerns of growing economic troubles in Europe. Here's how energy contracts traded Monday:

On the New York Mercantile Exchange:

Benchmark crude lost 6 cents to end at $104.87 per barrel;

Gasoline fell by 2.18 cents to end at $3.1844 per gallon;

Heating oil ended virtually unchanged at $3.1834 per gallon;

Natural gas rose 9.9 cents to end the day at $2.285 per 1,000 cubic feet.

On the ICE Futures exchange in London:

Brent crude lost 36 cents to end at $119.47 per barrel.