The boards of directors for Kmart Holding Corp. and Sears, Roebuck & Co. have unanimously approved the merging of the two major retailers in an $11 billion deal. The new company, if approved by the shareholders of both retailers, will be known as Sears Holdings Corp. In a conference call held by the two companies earlier today in New York City, Kmart Chairman Edward Lampert said the stores will be run under the Kmart and Sears nameplates, although Kmart stores will be turned into Sears outlets "where appropriate." (Sears CEO Alan Lacy estimated that there will be "several hundred" Kmart stores turned into Sears outlets.) "I think it´s pretty obvious that scale is very important to compete effectively," Lampert said. "We have to have a low cost structure to compete with our biggest competitors." That would be major retailers like Wal-Mart Stores Inc., the world´s largest retailer, and Target Corp. Both are opening stores at a faster rate than either Kmart or Sears.