Nortel to Cut 3,500 Jobs to Boost Profit  OTTAWA (Reuters) - Nortel Networks Corp. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=NT.TO target=/stocks/quickinfo/fullquote"&gt;NT.TO&lt;/A&gt; &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=NT.TO target=/stocks/quickinfo/fullquote"&gt;NT.TO&lt;/A&gt;  posted long-awaited preliminary results for the first half of  2004 on Thursday, estimating first and second quarter earnings  between nil and 1 cent per share.