Carnival Profit Cruises Up 43 Percent  NEW YORK (Reuters) - Carnival Corp. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=CCL.N target=/stocks/quickinfo/fullquote"&gt;CCL.N&lt;/A&gt;&lt;CCL.L&gt;, the  world's biggest cruise group, on Thursday posted a 43 percent  rise in quarterly earnings as it benefited from a merger with  P O Princess Cruises last year.