U.S. Cash Crude-Grades sideways on thin volumes

May 6 (Reuters) - U.S. cash crude differentials movedsideways on Friday on thin volumes, dealers said. The move follows a number of production facilities shuttingfollowing a raging wildfire that forced some 88,000 residents toflee Fort McMurray in Alberta, Canada, earlier this week. The closures of production caused a spike in Canadian crudeprices earlier, though volumes in the Canadian market were alsothinly traded on Friday. BP Plc will not be able to deliver on some contractsfor Canadian crude, two trading sources said on Friday, thelatest sign that output cuts due to the wildfires are curbingsupply from the oil sands region. Others wereexpected to follow. * Light Louisiana Sweet for June delivery rose 2cents to a midpoint of $1.92 and traded between $1.90 and $1.95a barrel premium to U.S. crude futures. * Mars Sour fell 5 cents to a midpoint of -$3.25and traded at a $3.30 a barrel discount to U.S. crude futures. * WTI Midland rose 2.5 cents to a midpoint of-$0.2 and traded between 20 and 25 cents a barrel discount toU.S. crude futures. * West Texas Sour rose 8 cents to a midpoint of-$1.27 and traded at a $1.25 a barrel discount to U.S. crudefutures. * WTI to East Houston traded at $1.65 a barrel over WTI. * ICE Brent July futures rose 36 cents to settle at$45.37 a barrel. * WTI June crude futures rose 34 cents to settle at$44.66 a barrel. * The Brent/WTI spread widened 5.0 cents tosettle at $-0.05. (Reporting by Catherine Ngai in New York; Editing by MatthewLewis)