UPDATE 1-Sears Holdings to close 12 stores

(Adds stores' locations)

ATLANTA, Oct 21 (Reuters) - U.S. retailer Sears Holdings Corp (SHLD.O) is planning to close 12 stores, including eight Kmarts and four Sears outlets, in January.

The closures are "part of our normal course of business of opening and closing stores," spokeswoman Kimberly Freely said, adding, "It's not part of a greater issue."

The stores to be closed include Kmarts in Marietta, Georgia; Phoenix and Mesa, Arizona; Forest Park, Ohio; Northridge, California; Clarksville, Indiana; Sarasota, Florida and Knoxville, Tennessee.

The company will also shutter a Sears Grand in Columbia, South Carolina; a Sears Essentials in St. Petersburg, Florida; and two other Sears stores in Indianapolis and Florissant, Missouri.

Sears Holdings, formed in the 2005 merger of Kmart and Sears, Roebuck, operates more than 3,000 stores.

(Reporting by Karen Jacobs, editing by Leslie Gevirtz)