Volume Spike Investor

Yahoo Inc. (Nasdaq: YHOO) shares are down more than 7 percent to $15.90 in early premarket trading of more than 100,000 shares; it was among the most active after-hours stocks, as well. The company confirmed a 10-year search-engine agreement with rival Microsoft Corp. (Nasdaq: MSFT) to jointly attack Google Inc’s (Nasdaq: GOOG) 65 percent search market share. The move may dampen some lingering expectations that Microsoft may still buy Yahoo. Microsoft technology will now power Yahoo search, and Yahoo will become the relationship sales force for both companies’ premium search advertisers. — Mike Tarsala