(Adds CEO comment, details from release)
NEW YORK, Jan 9 (Reuters) - Sears Holdings Corp's sales are slipping faster and faster.
The troubled retailer on Thursday reported declines in comparable-store sales at its Kmart and U.S. namesake chain for the crucial holiday season that were even sharper than for the third quarter.
At its U.S. Sears stores, sales at stores open at least one year, an industry benchmark known as comparable sales, were down 9.2 percent in the nine weeks that ended Jan. 6 and down 5.7 percent at Kmart.
Data firm ShopperTrak said this week that U.S. retail sales had risen 2.7 percent industrywide during the holidays.
Sears shares were down 13.3 percent at $36.90 in after-hours trading.
Sales at the company have been falling since 2005, when hedge fund manager Edward Lampert merged the two U.S. chains in an $11 billion deal.
"The results that we posted are not nearly what we want them to be," Lampert, Sears Holdings' chief executive and top shareholder, wrote in a blog post.
Retailers faced the most promotional holiday season since the recession, trying to outdo one another with deep discounts to lure shoppers. As a result, a number of retailers slashed their profit forecasts on Thursday.
Sears said it expects to post a lost of between $11.85 and $12.88 per share for the fiscal year ending Feb. 1. That includes a loss of $2.35 to $3.39 per share for the holiday quarter. (Reporting by Phil Wahba in New York; Editing by Andre Grenon and Leslie Adler)