American Air Posts Loss, Plans Job Cuts  DALLAS (Reuters) - American Airlines' parent AMR Corp.  &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=AMR.N target=/stocks/quickinfo/fullquote"&gt;AMR.N&lt;/A&gt; on Wednesday said record-high fuel costs pushed it to a  hefty third-quarter loss and warned it must cut costs and find  new revenue sources to survive in a world of soaring oil  prices.