Cingular to sell 33 stake in Idea to ST Telemedia and Telekom &lt;b&gt;...&lt;/b&gt; NEW YORK, December 13 (newratings.com) - Cingular Wireless, a joint venture between SBC Communications (SBC.NYS) and BellSouth Corporation (BLS), has agreed to sell its 33 stake in Indias fifth-largest mobile operator, Idea Cellular, to Singapore 