Judge Will Mull Voiding UAL Union Deals  CHICAGO (Reuters) - A federal bankruptcy judge agreed on  Friday to consider a motion by United Airlines &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=UALAQ.OB target=/stocks/quickinfo/fullquote"&gt;UALAQ.OB&lt;/A&gt; to  cancel its union contracts to save \$725 million annually.