Scana Third-Quarter Profit Falls  NEW YORK (Reuters) - U.S. power company Scana Corp &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=SCG.N target=/stocks/quickinfo/fullquote"&gt;SCG.N&lt;/A&gt;  on Friday said quarterly profit fell, on litigation costs and a  writedown related to an investment in a telecommunications  business.