Brent crude was down 53 cents, or 0.7 pc, at $71.47 a barrel by 1:25 p.m. EDT (1725 GMT). U.S. West Texas Intermediate oil declined 35 cents to $68.01 a barrel, snapping a three day rally.
The move higher may have been exacerbated by algorithmic traders selling Treasuries after the 10-year yields broke above their daily 200-day moving average.
The yields are in the middle of their recent range after falling from a one-month high of 1.379% on Aug. 12, while holding above a six-month low of 1.127% reached earlier this month.
Chinese blue chips shed 3.2% in the biggest daily decline since March, as the education and property sectors were battered due to concerns over tighter government rules.