Merck Maintains Quarterly Dividend  NEW YORK (Reuters) - Merck   Co. Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=MRK.N target=/stocks/quickinfo/fullquote"&gt;MRK.N&lt;/A&gt; has declared  its regular quarterly dividend, maintaining its status as one  of the richest dividend payors among blue-chip stocks, even  following the withdrawal of its arthritis drug Vioxx and  subsequent loss of nearly \$27 billion in market value.