Brent crude for December fell 32 cents, or 0.8%, to $42.53 a barrel by 0347 GMT and U.S. West Texas Intermediate for November was at $40.30 a barrel, down 30 cents, or 0.7%.
Brent was down by 9 cents at $43.25 a barrel by 0152 GMT, having gained more than 3% on Thursday. U.S. West Texas Intermediate (WTI) crude dropped 5 cents at $41.14 after also falling more than 3% on Thursday.
Oil and gas workers have withdrawn from offshore US Gulf production facilities as Hurricane Delta was forecast to intensify into a powerful, Category 3 storm.
Brent crude futures lost 74 cents, or 1.7pc, to $41.91 a barrel by 1009 GMT and US West Texas Intermediate (WTI) crude declined by 89 cents, or 2.2pc, to $39.78.
Hurricane Delta, the 25th named storm of the 2020 Atlantic Hurricane season, was churning in the Caribbean with sustained winds of 140 miles per hour.
Royal Dutch Shell Plc said on Tuesday it was evacuating nonessential workers from all nine of its offshore Gulf of Mexico operations and preparing to shut production.
There were no plans to move jobs abroad and it was engaging with its workforce on the plan.
Prices of oil, Nigeria's main export, fell sharply early this year and in April global benchmark Brent hit a 21-year low below $16 as the coronavirus outbreak hit demand.
The benchmark palm oil contract for December delivery on the Bursa Malaysia Derivatives Exchange closed 2.8pc lower to 2,715 ringgit ($652.33) a tonne.
Brent crude futures fell $1.64, or 3.9pc, to $40.66 a barrel by 1401 GMT and US West Texas Intermediate (WTI) crude futures were down $1.75, or 4.4pc, at $38.47.