Yahoo has reported a stronger-than-expected first-quarter profit, results hailed by chief executive Marissa Mayer as showing growth in the web giant's "core" business.
The California internet company said it earned $US312 million ($A332.39 million) on revenues of $US1.1 billion, topping most analyst forecasts.
Profits were down 20 per cent from a year ago with revenues nearly flat, with Yahoo has been making major shifts under Mayer, a former Google executive.
Mayer said the first quarter data "was an early and important sign of growth in our core business."
"And, with mobile pivotal to our future growth, we're delighted to now see more than 430 million monthly mobile users accessing Yahoo's new products," she said in the earnings release.
Yahoo shares vaulted higher by some eight per cent in after-hours trade following the release to $US37.
Under Mayer, Yahoo has been revamping many of its offerings while emphasising mobile services and using cash for a series of acquisitions.
Yahoo is also moving more into video, with plans for its original television programs in the works.
Yahoo is also a key shareholder in Chinese web giant Alibaba, which is in the process of launching an initial public offering in the United States.
After an IPO, Yahoo, one of the early investors in Alibaba, has the right to sell its remaining shares.
