Yahoo has confirmed that Bartz is no longer CEO but no further details were immediately available, .
Bartz saying that she'd been fired by Yahoo's chairman, according to the TechCrunch website.
"I am very sad to tell you that I've just been fired over the phone by Yahoo's Chairman of the Board. It has been my pleasure to work with all of you and I wish you only the best going forward," Bartz wrote to employees, according to TechCrunch.
Yahoo did not immediately return calls seeking comment.
Bartz's tenure as CEO began in January 2009 after Yahoo co-founder Jerry Yang announced plans to step down. She took over following an extensive courtship in which Microsoft had tried to acquire Yahoo, but which eventually turned into a partnership between the companies.