BellSouth: Retiree Costs to Cut Q4 Earns  WASHINGTON (Reuters) - BellSouth Corp. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=BLS.N target=/stocks/quickinfo/fullquote"&gt;BLS.N&lt;/A&gt; said on  Wednesday its new labor contract had triggered a \$3.3 billion  increase in its estimates of future retiree medical costs,  reducing fourth-quarter earnings by 3 cents to 4 cents a share.