FILE - In this Jan. 7, 2008 file photo, Yahoo CEO Jerry Yang, left, and David Filo are seen during Yang's keynote address at the Consumer Electronics Show (CES) in Las Vegas. Yahoo Inc. invested billions of dollars in its Internet search engine during the past six years before realizing it made more sense to entrust the job to an outsider _ something the company's co-founders concluded shortly after they started a Web directory in the mid-1990s. This week's deal with Microsoft closes another chapter in an influential Web pioneer that has seen many of them.