Yahoo gets new CEO: Well-respected Google exec Marissa Mayer

— -- SAN FRANCISCO — Longtime Google executive Marissa Mayer— one of Silicon Valley's best-known personalities — starts work today as Yahoo CEO, becoming one of the most prominent female leaders in business.

The struggling Internet giant announced Monday that it is turning to Mayer, 37 — its fifth CEO in five years — to spearhead a massive turnaround effort that has gained little traction the past few years.

Mayer succeeds interim CEO Ross Levinsohn, who took over for the ousted Scott Thompson, who was shown the door on Mother's Day following résumé inaccuracies. Thompson took over for Carol Bartz earlier this year, after she was shown the door.

At Google, Mayer earned kudos for her management of several key technologies and a reputation as a demanding perfectionist. She molded the look and feel of some of the company's best known, and used, products — services such as Google's search, Gmail and Google News.

The appointment of Mayer, employee No. 20 at Google and one of its few public faces, could perk up spirits among Yahoo employees and investors. Industry analysts such as Jonathan Yarmis called it a PR master stroke for Yahoo, which has struggled mightily to attract, and keep, top-flight talent in its competitive battle with Google and Facebook.

"I'm surprised and impressed," says Yarmis, an analyst at HfS Research who thinks Mayer's hiring could aid in recruiting efforts. "Yahoo has been able to attract someone of the highest caliber here, someone who understands the business. This is really the first thing out of Yahoo in a decade that you can't snicker at. She's the kind of person you didn't think Yahoo could get."

Wall Street applauded the news, lifting Yahoo shares 2% to $15.98 in after-hours trading.

"I am honored and delighted to lead Yahoo, one of the Internet's premier destinations for more than 700 million users," Mayer said in a statement.

Mayer, Google's first female engineer, joins a short list of female tech CEOs at large public companies. The elite club includes Hewlett-Packard CEO Meg Whitman and IBM CEO Virginia Rometty. Sheryl Sandberg, Facebook's chief operating officer, essentially runs day-to-day operations.

"I am personally very excited to see another woman become CEO of a technology company," Google Executive Chairman Eric Schmidt said in a statement.

During her 13 years at Google, Mayer was responsible for shaping Google's most popular products — ranging from its search homepage to Gmail and Google Images. Recently, she oversaw the company's location and local services, including Google Maps, encompassing more than 1,000 product managers.

Mayer also sat on Google's operating committee that advised Google co-founders Larry Page and Sergey Brin.

Google CEO Page, in a statement, called Mayer "a tireless champion of our users."

As an early Google employee, Mayer was also something of a celebrity in Silicon Valley. She often spoke at high-profile tech conferences, posed in fashion spreads, including Vogue, was frequently reported in local high-society columns and lived in a posh penthouse in San Francisco's Four Seasons. She's also a connoisseur of cupcakes.

Still, the move to Yahoo is an opportunity for Mayer to claim a bigger stage.

"This is a Hail Mary pass," says Peter Shankman, an independent marketing strategist based in NYC. "If this one doesn't do it, the clock has pretty much ticked out."

A ticklish to-do list