Yahoo CEO Marissa Mayer.  Reuters

Marissa Mayer, the new CEO of Yahoo Inc., the No. 3 search engine, cleaned house again, this time adding an e-commerce specialist to the board while ousting two others.

With the OK of minority investor and director Daniel Loeb, Mayer had the board elect Max Levchin, 54, as the newest director of the Sunnyvale, Calif.-based company. He was a co-founder of PayPal, now a unit of eBay (NASDAQ:EBAY), then founded Slide, which was later sold to Google (NASDAQ:GOOG).

Mayer, 37, was a Google VP until he was recruited to Yahoo in July. “Max is someone I've admired throughout my career,” she said.

Two directors who served short terms said they will retire. They are David Kenny, 50, now CEO of The Weather Channel, a unit of Comcast Corp. (NASDAQ:CMCSA), and Brad Smith, 45, CEO of Intuit (NASDAQ:INTU). Kenny served 11 months on the board while Smith served two years.

Shares of Yahoo fell 3 cents to $19.35 on Thursday. Under Mayer, they've gained 23 percent.