Qualcomm May Change Accounting,Shares Off  CHICAGO (Reuters) - Qualcomm Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=QCOM.O target=/stocks/quickinfo/fullquote"&gt;QCOM.O&lt;/A&gt;, a maker of  chips used in mobile phones, on Friday said it may change the  way it recognizes royalties from licensees, which would reduce  fourth-quarter pretax income by \$298 million.