Oil prices dipped on Friday, erasing earlier gains, as concerns about rising new coronavirus cases in the United States and China and expectations of US output ticking up while crude stockpiles linger at record highs.
Brent crude futures were 17 cents lower at $40.88 at 1233 GMT. US West Texas Intermediate (WTI) crude futures were 39 cents at $38.33, erasing previous gains.
The contracts are on track for weekly falls of around 3 percent and 3.5 percent, respectively, after record US crude inventory data dragged prices down on Wednesday.
The prospect of increased US crude production also kept a lid on gains on Friday.
A survey of executives in the top US oil and gas producing region by the Dallas Federal Reserve Bank found more than half of executives who cut production expect to resume some output by the end of July.