Blue Chips Fall on Oil, Apple Lifts Techs  NEW YORK (Reuters) - U.S. blue-chip stocks fell on Monday  as oil prices nudged higher and as drug maker Pfizer Inc.  &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=PFE.N target=/stocks/quickinfo/fullquote"&gt;PFE.N&lt;/A&gt; and aluminum producer Alcoa Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=AA.N target=/stocks/quickinfo/fullquote"&gt;AA.N&lt;/A&gt; were hit by  broker downgrades.