American Gilsonite Co., 136 E. South Temple, which controls the world's largest known reserve of Gilsonite resin, had net income of $299,171 for the quarter ending June 30 compared with a net loss of $416,370 in the same quarter a year ago.

For the six months ending June 30, the company had net income of $480,213 compared with a net loss of $649,804 in the same period of 1993. Company officials attributed the improved financial results to increased sales of its value-added products, complemented by improved efficiencies, which reduced production costs for the quarter by $120,000.Gilsonite is a nonhazardous, naturally occurring hydrocarbon resin used primarily in printing inks, foundry sands, oil- and gas-well drilling muds, oil-well cements, asphalt, building materials, paints and protective coatings.