(Compares with estimates, adds details, share move)
Nov 10 (Reuters) - Department store chain J.C. Penney Co Inc reported third-quarter same-store sales that were twice what it had estimated, sending its shares up 9 percent in premarket trading on Friday.
The retailer said comparable sales rose 1.7 percent, better than the 0.6-0.8 percent rise it had forecast last month.
Analysts on average had expected comparable sales to increase 0.7 percent, according to Thomson Reuters I/B/E/S.
J.C. Penney last month also slashed its full-year forecast as it sold stagnant apparel inventory at heavy discounts amid an overhaul of its women's section.
Rivals such as Macy's and Nordstrom reported a decline in quarterly comparable sales on Thursday, as store closures due to hurricanes added to their ongoing troubles of weak mall traffic and losing customers to online shopping.
J.C. Penney's net loss widened to $128 million, or 41 cents per share, in the quarter ended Oct. 28, from $67 million, or 22 cents per share, a year earlier, partly due to heavy discounting to clear slow-moving inventory.
Excluding items, the company reported a loss of 33 cents per share, smaller than the 40-45 cents loss it had estimated. Analysts had expected a 43 cent loss.
Net sales fell about 2 percent to $2.81 billion, but beat the average analyst estimate of $2.77 billion. (Reporting by Sruthi Ramakrishnan in Bengaluru; Editing by Maju Samuel and Sriraj Kalluvila)