Benchmark West Texas Intermediate crude gave up $1.95 to $98.55 per barrel in New York while Brent crude lost $1.46 to $107.82 in London. Stocks were down about 1 percent.
Prices slipped after the European Central Bank disappointed investors with only modest steps to revive its troubled economy. The ECB cut interest rates, but officials said there was no plan for major government bond purchases.
Concerns about Europe overshadowed positive news in the U.S. The Labor Department said that people applying for unemployment benefits fell last week to the lowest level in nine months.
At the pump, retail gasoline prices rose by nearly a penny overnight to $3.295 per gallon.