Lowe's Profit Rises, But Stock Falls  ATLANTA (Reuters) - Home improvement retailer Lowe's Cos.  Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=LOW.N target=/stocks/quickinfo/fullquote"&gt;LOW.N&lt;/A&gt; on Monday reported a 15 percent rise in  third-quarter profit, aided by its expansion to New York and  other big U.S. markets, but its stock fell on a disappointing  outlook and concern about profit margins.