SAN FRANCISCO (AFP) - Facebook on Wednesday reported that is quarterly profit more than doubled amid big gains in ad revenues and a jump in users. Net income leapt to US$791 million (S$978.8 million) during the three months ended June 30 in a 138 per cent increase from the US$333 million made during the same period a year earlier, the world's biggest social network said.

"We had a good second quarter," Facebook co-founder and chief executive Mark Zuckerberg said in the earnings release. "Our community has continued to grow, and we see a lot of opportunity ahead as we connect the rest of the world."

Revenue in the quarter surged to US$2.91 billion, with approximately 62 per cent of that money coming from ads served up on mobile devices such as smartphones or tablet computers.

Ad revenues overall were up 67 per cent from a year ago to US$2.68 billion.

Cashing in on the trend of Facebook members increasingly using mobile devices to connect to the social network has been seen by analysts as vital to its success.

The number of people who visited the online social network at least once a month climbed to 1.32 billion in a 14 per cent rise from the same quarter last year, according to Facebook.