J.C. Penney Co., the department-store chain working to rebound from a $985 million loss, said its sales decline slowed in September and that the improvement will last through the end of the year. Sales at stores open at least 12 months fell 4 percent in the fiscal month ended Oct. 5, the Plano, Texas-based company said today in a statement. Same-store sales dropped 12 percent in the quarter through Aug. 3.