* Crude futures fall on weak employment data * Brent premium to U.S. crude back above $2/bbl NEW YORK, Aug 1 (Reuters) - Cash crude differentials in theUnited States were mixed on Friday and for the most part littlechanged as crude futures slumped in reaction to disappointingU.S. employment data, traders and brokers said. Brent and U.S. crude futures came under pressure whengovernment data showed fewer jobs were added in the UnitedStates in July than analysts expected, tempering optimism aboutthe economy that had pushed oil prices higher this week. The cash market shrugged off the wider transatlantic spreadbetween Brent and U.S. crude futures, traders said. Brent crude's premium to U.S. crude futures ,also known by the benchmark crude grade, West Texas Intermediate(WTI), ended at $2.01 a barrel based on September contractsettlements after closing at $1.65 on Thursday. The spread onFriday ranged from $1.14 to $2.19. Brent's premium reached $4.01 intraday on Tuesday. Usually, the wider the arbitrage, the more supportive it isfor U.S. cash crude differentials, while a narrower spread oftenpressures differentials. This holds especially true for sweetgrades, which are priced in line with global waterborne crudessuch as Brent. CASH CRUDE TRADES Light Louisiana sweet crude oil for September tradedfrom $4.50 to $5.00 over the September U.S. light sweet crudefutures contract. That range contrasted with Thursday'strades completed from $4.80 to $5.15 over the futures benchmark. Heavy Louisiana sweet traded at $4.50 over thebenchmark futures, slightly stronger after trading on Thursdayat $4.35 over the benchmark. Mars sour crude, a Gulf of Mexico-produced grade, hadSeptember barrels traded at 20 and 30 cents under the futuresbenchmark after trading on Thursday at 20 and 25 cents under thebenchmark. October Mars crude traded on Friday at $1.30 and $1.40 underthe futures benchmark, weaker after trading on Thursday at 95cents under the benchmark. Traders and brokers had expected Mars to be pressured byRoyal Dutch Shell Plc's anticipated work on thesoutheast Texas-to-Louisiana portion of its Houma-to-Houstoncrude oil pipeline this month to finish reversing the line tomove crude oil from Texas into Louisiana. Shell said on Thursday that it shut the line, but did notgive a specific restart date, stating only that the fullyreversed service would be operational by the end of 2013. The work and the reversal of the pipeline limits the marketsavailable to easily send Mars crude. Mars and other Gulf of Mexico sour grades had been supportedby news on July 17 that Shell was shutting down its offshoreAuger production platform for work. Crude from the Augerplatform feeds the Bonito sour stream. Bonito sour traded on Friday at $2.50 over the futuresbenchmark, steady after Thursday's trading at the samedifferential. Eugene Island crude also traded at $2.50 over thefutures benchmark, steady to Thursday's differential. MIDLAND GRADES West Texas Intermediate crude at Midland forSeptember traded at 25 cents under the futures benchmark aftertrading at 20 cents under on Thursday. West Texas Sour crude, also at Midland, had buyerbids pegged at 10 cents under the benchmark, with seller offerssteady at flat to the futures benchmark, where it traded onThursday. CRUDE FUTURES Brent September crude fell 59 cents to settle at$108.95 a barrel. U.S. September crude fell 95 cents tosettle at $106.94 a barrel. (Reporting by Robert Gibbons. Editing by Andre Grenon)