JC Penney said Tuesday that a closely-watched sales measurement grew in November and December, and its shares climbed in aftermarket trading.

The company said sales at stores open at least a year grew 3.7 percent in November and December. Sales at stores open at least a year are considered an important measurement of retailer performance because they exclude results from stores that have opened or closed within the last year.

JC Penney has said those sales should grow 2 to 4 percent in the fourth quarter. Based on its November and December results, the Plano, Texas-based company now expects to reach the high end of that range.

Shares of JC Penney Co. rose 12 cents to $6.56 Tuesday and jumped $1.09, or 16.6 percent, to $7.65 in aftermarket trading.