Agere to Cut 500 Jobs, Book Charges  NEW YORK (Reuters) - Communications chip maker Agere  Systems Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=AGRa.N target=/stocks/quickinfo/fullquote"&gt;AGRa.N&lt;/A&gt; on Wednesday said it will cut 500 jobs  and sell or close a plant in Florida that employs 600 people in  order to reduce costs amid slowing sales.