Sunnyvale, Calif. -- Marking its fifth CEO since September, Sunnyvale-based Yahoo late Monday named former Google executive Marissa Mayer as its new head, tasking the 37-year-old with turning around the struggling Internet company. Mayer succeeds Ross Levinsohn, who in May replaced Scott Thompson on an interim basis after Thompson was forced to step down amid allegations that he misrepresented his academic credentials. The company's leadership carousel began in September, when it fired Carol Bartz, appointing Tim Morse as interim CEO. Yahoo said its latest higher signals a "renewed focus on product innovation to drive user experience and advertising revenue." Mayer most recently served as the vice president of local, maps and location services at Google where she oversaw products such as Google Maps, Google Earth, Zagat, Street View and local search. She also curated the Google Doodle program, celebrating special events on the company's homepage. Mayer joined Google as its first female engineer in 1999. "Marissa is a well-known, visionary leader in user experience and product design and one of Silicon Valley's most exciting strategists in technology development," said Yahoo co-founder David Filo.