Technology firm Yahoo has appointed leading Google executive Marissa Mayer as its next chief executive. Mayer, 37, will become the firm's third CEO in the space of a year.

According to BBC, in a statement released by Yahoo, Mayer said she was "honored and delighted" to lead the company.

In May CEO Scott Thompson stepped down after accusations that he put a fake computer degree on his CV. In September 2011, CEO Carol Bartz was fired after two-and-a-half years in the post.

Yahoo has struggled in the face of increased competition from search rivals including Google and the emergence of social giants such as Facebook.

Although it remains the U.S.' largest web portal, correspondents say Yahoo's failure to become more "social" has hurt the firm. Yahoo's news service still attracts very large volumes of traffic. But other products, such as its search engine and email, have suffered. The company's revenue from display advertising has also dwindled.

Correspondents say the selection of Mayer to head the company suggests a renewed focus on technology and products, over online content.

"I look forward to working with the company's dedicated employees to bring innovative products, content, and personalized experiences to users and advertisers all around the world," Mayer said.

Meanwhile, according to some reports, Mayer is pregnant and due in October.