Oil prices slip amid weak demand

    By Nicole Friedman     Oil prices slipped Tuesday on indications that weak global demand is set to continue.     Light, sweet crude for October delivery fell $1.09, or 1.1%, to $94.87 a barrel on the New York Mercantile Exchange. The Nymex floor was closed Monday for Labor Day.     Brent oil fell $1.15, or 1.1%, to...