By 0641 GMT, Brent crude futures were down 33 cents, or 0.8 percent, to $ 41.39 a barrel, and earlier fell 1.2 percent to $ 40.21.
US West Texas Intermediate crude futures fell 40 cents, or 1 percent, to $ 39.40, after dropping 1.4 percent to $ 36.26.
The two benchmarks fell more than 4 percent on Monday, the biggest decline in two weeks, but both rose on Tuesday.
Concerns about fuel demand have renewed with the rise in cases of Coronavirus in countries including France and Spain, as well as the possibility of further restrictions in Britain.
In the United States, where deaths due to disease exceeded 200,000, the highest in the world, crude oil inventories rose by 691,000 barrels in the week ending September 18, according to sector data, compared with analysts’ expectations for a decline of 2.3 million barrels.
Gasoline stocks fell by 7.7 million barrels, almost eight times what is expected, indicating some demand for fuel in the world’s largest oil-consuming country, but the jump in Covid-19 cases in many countries raises question marks about the extent of global demand recovery.