	dupont dd unit raises  oil prices conoco inc a subsidiary of dupont corp said it was increasing its contract prices for  oil between cts and one dlr a barrel effective today conoco said the increase brings its price for the u s benchmark  west texas intermediate to dlrs a barrel up one dlr south louisiana sweet also up one dlr is now dlrs west texas sour was up cts to dlrs a barrel conoco was the last company to raise prices following a series of increases initiated last week by sun co sun which reversed the posted price cuts made at the end of february reuter 
