Stocks Rise After Fed Hikes Rates  NEW YORK (Reuters) -  U.S. stocks extended their gains  slightly before stabilizing on Tuesday, after the Federal  Reserve hiked interest rates by an expected quarter-point,  while technology stocks were sparked by a report that Veritas  Software Corp. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=VRTS.O target=/stocks/quickinfo/fullquote"&gt;VRTS.O&lt;/A&gt; would be taken over.