Yahoo! fired Chief Executive Carol Bartz with a phone call from the company’s chairman, reports Bloomberg.

Bartz sent a memo to the company’s employees Tuesday to let them know she was terminated by Chairman Roy Bostock, the story notes.

“I am very sad to tell you that I’ve just been fired over the phone by Yahoo’s chairman of the board,” Bartz said in the memo. “It has been my pleasure to work with all of you and I wish you only the best going forward.”

Bostock, who helped hire Bartz in January 2009, declined to comment, according to the story.

Chief Financial Officer Tim Morse will serve as interim CEO, the story adds.

Bartz’s reign at Yahoo has been frustrating to investors, as the company has failed to keep Google and Facebook from wooing away its Internet users and ad revenue, the story notes.