Yahoo reported Tuesday a 93 percent slide in quarterly profit from a year ago while revenues rose, as struggling Internet pioneer released disappointing results.

Net profit for the first quarter tumbled to $21.1 million from $312 million in the same period last year, amid what chief executive Marissa Mayer called "encouraging revenue growth" of eight percent.

Total revenue for the first three months of the year grew to $1.23 billion, led by gains in "search revenue," from ads linked to queries using Yahoo's search function.

But revenue and profit were both lower than Wall Street forecasts, and Yahoo's shares slipped in after-market trade by 2.1 percent.

"Yahoo is amidst a multi-year transformation to return an iconic company to greatness," Mayer said in the earnings statement.

"This quarter, we saw encouraging revenue growth of eight percent, with display revenue growing a modest two percent and search growing 20 percent."

She said mobile revenues reached $234 million in the quarter, up 61 percent from a year ago.

Mayer said the Internet giant will now focus on "accelerating" revenue growth "while managing our margins and costs."

Yahoo has been under pressure from activist shareholders to deliver more value with lower costs and a narrower focus.

The California group, which recently celebrated its 20th anniversary, has been undergoing a major reorganization since Mayer took the helm in 2012.

The efforts have included a divestment of a large part of its stake in Chinese online giant Alibaba, along with a series of acquisitions.

Mayer spent more than $1 billion to acquire the blogging platform Tumblr to reach a younger market segment, and has made a push to focus more on mobile content and search.

In the past quarter, its search volume reached a five-year high, helped by a partnership with Mozilla, which made Yahoo the browser's default search engine.

But it remains far behind market leader Google in the search market.