Ex-CA Chief Pleads Not Guilty to Fraud  NEW YORK (Reuters) - Former Computer Associates  International Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=CA.N target=/stocks/quickinfo/fullquote"&gt;CA.N&lt;/A&gt; Chief Executive Sanjay Kumar pleaded  not guilty on Thursday to charges of securities fraud and  obstruction of justice after a two-year investigation into the  company's accounting practices.