Host Marriott Quarterly Loss Narrows  NEW YORK (Reuters) - Hotel owner Host Marriott Corp.  &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=HMT.N target=/stocks/quickinfo/fullquote"&gt;HMT.N&lt;/A&gt; on Wednesday said its third-quarter loss narrowed as  revenue per room rose, driven by an increase in room rates.