United Air Raises Fuel Surcharge  NEW YORK (Reuters) - UAL Corp. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=UALAQ.OB target=/stocks/quickinfo/fullquote"&gt;UALAQ.OB&lt;/A&gt; , the parent of  United Airlines, said on Friday it would raise its existing \$10  each-way fuel surcharge by an additional \$5 due to soaring fuel  costs.