Aetna Ends Magellan Mental Health Deal  CHICAGO  (Reuters) - Aetna Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=AET.N target=/stocks/quickinfo/fullquote"&gt;AET.N&lt;/A&gt; on Wednesday said  it will end its contract with Magellan Health Services &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=MGLN.O target=/stocks/quickinfo/fullquote"&gt;MGLN.O&lt;/A&gt;  for mental health coverage and bring those services in-house,  pushing shares of Magellan down about 3.5 percent.