Updated from 12:55 p.m. EDT with Yahoo!'s announcement that Scott Thompson is no longer CEO and that the company has settled proxy dispute with Daniel Loeb.SUNNYVALE, Calif. ( TheStreet) -- Yahoo! ( YHOO) Sunday announced that CEO Scott Thompson has stepped down and that the company has reached a settlement with activist hedge fund manager Daniel Loeb's Third Point LLC. In a news release, the Internet company said it had appointed Ross Levinsohn, Yahoo!'s global head of media, to serve as interim CEO, effective immediately.