HOFFMAN ESTATES, Ill.

Sears keeps pruning its business in a years-long makeover, a bid to transform itself from a 123-year-old retail store into a nimble, 21st century operator.

Patience appears to be wearing thin. Shares slid early Tuesday to 13-year lows after the company said it would accelerate the closure of some of its stores following a “challenging” holiday season. The company’s stock is down 20 percent this year, and they’ve been cut in half in the past 12 months.

Comparable-store sales in the fourth quarter dropped 6.9 percent at Sears, and 7.2 percent at Kmart, which the company also owns. That’s a key indicator of a retailer’s health because it excludes the volatility from stores recently opened or closed.

While the quarter that contains the critical shopping season was better compared with the previous three quarters, overall same store sales fell 9.2 percent in 2015, with Sears stores leading the decline.

“The holiday selling season proved to be challenging, with historically warm weather and intense competition pressuring margins and driving comparable store-sales declines,” the company said in a printed statement Tuesday.

Sears Holdings Corp. has struggled for years with weakening sales, unable to keep up with companies that sell appliances, like Home Depot, or general merchandise, like Wal-Mart, or everything, as is the case with Amazon.com.