Oil fell slightly to below $91 a barrel Monday in Asia, maintaining most of the big gains from the previous session after the U.S. reported better than expected jobs growth. Benchmark crude was down 50 cents at $90.90 a barrel at late afternoon Singapore time in electronic trading on the New York Mercantile Exchange. The contract rose $4.27 on Friday to settle at $91.40 in New York. In London, Brent crude was down 24 cents at $108.70 on the ICE Futures exchange. The Labor Department said Friday that U.S. employers added 163,000 jobs in July, the most since February. In other Nymex energy trading, wholesale gasoline futures were down 1.4 cents at $2.92 a gallon and heating oil slid 0.3 cent to $2.92. Natural gas fell 6.7 cents at $2.81 per 1,000 cubic feet, according to a report of the Associated Press.