PeopleSoft Ousts CEO Amid Oracle Battle  SAN FRANCISCO/NEW YORK (Reuters) - Oracle Corp.'s &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=ORCL.O target=/stocks/quickinfo/fullquote"&gt;ORCL.O&lt;/A&gt;  hostile bid for rival PeopleSoft Corp.&lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=PSFT.O target=/stocks/quickinfo/fullquote"&gt;PSFT.O&lt;/A&gt; was strengthened  on Friday as U.S. antitrust regulators dropped their case  against the merger and PeopleSoft fired its chief executive,  Craig Conway, who had led the fight against Oracle.