PLANO, Texas (AP) – J.C. Penney Co. says sales rose 6.4 percent at established locations in the third quarter and its gross margin improved, driven by supply chain productivity and improvements in margins for its sale items. The company is expressing confidence in its ability to compete in the upcoming holiday shopping season. For the full year, it expects sales to be up between 4 to 5 percent at established locations from the previous year. The struggling department store operator reported a loss for the quarter that ended Oct. 31, but it was less than analysts expected. The company says its loss narrowed to $137 million, or 45 cents per share. Adjusted for one-time gains and costs, losses came to 47 cents per share. Analysts had forecast a steeper loss of 58 cents per share. Revenue rose to $2.9 billion, also exceeding Wall Street forecasts.