Talk of a possible takeover of Nextel Communications reemerged following a canceled appearance at a conference. Nextel's chief technical officer canceled a presentation at an investor conference sponsored by BT Alex. Brown, citing scheduling conflicts. The wireless telephone company has been at the center of rumor speculation for more than a year, although Nextel's financial chief has said previously the company does not need a merger partner. Nextel call options were active following the news, according to a Reuters report.