Andrew Tumbles in Before-The-Bell Trade  NEW YORK (Reuters) - Shares of Andrew Corp. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=ANDW.O target=/stocks/quickinfo/fullquote"&gt;ANDW.O&lt;/A&gt; slid  11 percent before the bell on Thursday after the  telecommunications equipment maker forecast a quarterly loss  and weaker-than-expected revenue.