Merck Cuts More Jobs as Earnings Decline  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;, whose  earnings are being hurt by the withdrawal of its arthritis drug  Vioxx, said on Tuesday it has increased the number of jobs to  be cut by year-end to 5,100 from 4,400.