Coca-Cola Warns on Profits, Shares Drop  CHICAGO (Reuters) - Coca-Cola Co. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=KO.N target=/stocks/quickinfo/fullquote"&gt;KO.N&lt;/A&gt; on Wednesday said  earnings for the rest of the year would lag Wall Street  expectations because of weakness in key markets, further  highlighting the divergent fortunes of the world's largest soft  drink maker and its top rival, PepsiCo Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=PEP.N target=/stocks/quickinfo/fullquote"&gt;PEP.N&lt;/A&gt;.