Citigroup Elevates Krawcheck to CFO Post  NEW YORK (Reuters) - Citigroup Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=C.N target=/stocks/quickinfo/fullquote"&gt;C.N&lt;/A&gt; named Sallie  Krawcheck chief financial officer on Monday, extending her  reach across the world's largest financial services company and  bolstering her image as Wall Street's most powerful woman.