PC Sector Sale by IBM Would Signal Change International Business Machines Corp. has steadily lost its hold on the PC market, buffeted by made-to-order rivals such as Dell Inc. and low-cost competition from overseas. &lt;FONT face="verdana,MS Sans Serif,arial,helvetica" size="-2" color="#666666"&gt;&lt;B&gt;-The Washington Post&lt;/b&gt;&lt;/font&gt;