Wal-Mart to Cut Prices After Poor Sales  NEW YORK (Reuters) - Wal-Mart Stores Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=WMT.N target=/stocks/quickinfo/fullquote"&gt;WMT.N&lt;/A&gt;, the No.  1 U.S. retailer, on Tuesday signaled it will cut prices through  Christmas after holding back deep discounts on the first  weekend of the holiday shopping season.