Facebook first

Credit: Reuters/Dado Ruvic

A smartphone user shows the Facebook application on his phone in the central Bosnian town of Zenica, in this photo illustration, May 2, 2013.

Shares of Facebook were up nearly 3 percent at $63.05 in after-hours trading on Wednesday.

Facebook said that mobile ads represented 59 percent of its ad revenue in the first quarter, up from 30 percent in the year-ago period. Facebook's overall revenue grew 72 percent year-on-year to $2.5 billion in the first quarter, above the $2.36 billion expected by analysts polled by Thomson Reuters I/B/E/S.

Facebook also announced that Finance Chief David Ebersman is resigning. Ebersman, who will remain with the company through September, will be replaced by David Wehner, Facebook's vice president of corporate finance and business planning.

The world's No.1 Internet social network said its total number of monthly active users reached 1.28 billion as of March 31, with 1.01 billion of those users accessing its service on mobile devices such as smartphones and tablets.

The company said it earned $642 million in net income, or 25 cents a share, in the first quarter, versus $219 million, or 9 cents a share in the year ago period. Excluding certain items Facebook said it earned 34 cents a share in the first quarter.

(Reporting by Alexei Oreskovic; Editing by Cynthia Osterman)