Sears, KMart to Merge in \$11 Billion Deal  NEW YORK (Reuters) - Sears, Roebuck   Co. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=S.N target=/stocks/quickinfo/fullquote"&gt;S.N&lt;/A&gt; and  discount retailer Kmart Holding Corp. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=KMRT.O target=/stocks/quickinfo/fullquote"&gt;KMRT.O&lt;/A&gt; on Wednesday  said they would merge in an  \$11 billion deal to form the  third-largest U.S. retailer.