International crude benchmarks slipped on Thursday, with ICE Brent October futures settling at $66.43 a barrel, a decline of 46 cents or 0.69%. NYMEX West Texas Intermediate September contracts finished at $63.88 a barrel, down 47 cents or 0.73%. In refined products, September gasoline on NYMEX closed at $2.0861 a gallon, while September diesel settled at $2.2793 a gallon. September natural-gas futures ended the session at $2.99 per million British thermal units.