The West Texas Intermediate for November delivery fell 0.19 U.S. dollar to settle at 52.45 dollars a barrel on the New York Mercantile Exchange, while Brent crude for December delivery rose 0.02 dollar to close at 57.71 dollars a barrel on the London ICE Futures Exchange.
The Institute for Supply Management (ISM) said Thursday its reading on the U.S. services sector fell last month to its lowest level since August 2016.
The non-manufacturing index registered 52.6 percent, 3.8 percentage points below the August reading of 56.4 percent, according to ISM's report. The figure was also lower than the estimated reading of 55.3 from economists surveyed by Dow Jones.
It followed data from the ISM on Tuesday showing that business activity in the manufacturing sector contracted in September.
The U.S. manufacturing PMI (purchasing managers' index) registered 47.8 percent, the lowest since June 2009, marking the second consecutive month of contraction, according to the report.
Meanwhile, the energy market was partly bolstered by the supply side as various surveys showed that the Organization of the Petroleum Exporting Countries oil production declined in September amid the attacks on Saudi oil facilities.
Concern about the worsening economic outlook has overshadowed support from the supply side, experts noted.