Stocks Open Lower; Intel, Oil Stocks Down  NEW YORK (Reuters) - U.S. stocks opened slightly lower on  Monday as chip maker Intel Corp. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=INTC.O target=/stocks/quickinfo/fullquote"&gt;INTC.O&lt;/A&gt; fell after a broker  downgrade, weakening technology shares, while a drop in crude  prices hurt energy companies such as Exxon Mobil Corp &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=XOM.N target=/stocks/quickinfo/fullquote"&gt;XOM.N&lt;/A&gt;.