Marissa Mayer, one of Google's top executives, will be the next chief of Yahoo, making her one of the most prominent women in Silicon Valley and corporate America.

Mayer's appointment is considered a coup for Yahoo, which has struggled in recent years to attract top talent in its battle with competitors. One of the few public faces of Google, Mayer, 37, has been responsible for the look and feel of some of its most popular products.

Mayer will face a daunting challenge.

A pioneering Internet company that helped shape the industry in the 1990s, Yahoo is trying to remain relevant after failing to adapt to changing innovations like sophisticated search technology and social-media tools.

The big question is whether Mayer, or anyone, can help Yahoo regain its clout.

"It's a very interesting departure and a very interesting choice," said Martin Sorrell, chief executive of WPP, the giant advertising agency. "She comes with a formidable reputation, but we'll see how she analyzes it all."

Mayer will be Yahoo's fifth CEO — two of them interim — in less than a year.

Mayer, an engineer whose first job at Google included computer programming, was behind the famously unadorned white search home page and the way users interacted with Gmail, Google News and Google Images.

She revealed Monday night to Fortune magazine she will give birth to her first child this fall and had told the Yahoo board of that before it voted unanimously to hire her.