Facebook rose in late trading yesterday after chief executive officer Mark Zuckerberg said he's addressing the missteps that have made it hard to reap the benefits of mobile advertising.

"Now we are a mobile company," Mr Zuckerberg said in an on- stage interview at the TechCrunch Disrupt conference in San Francisco yesterday, his first since Facebook's initial public offering.

"Over the next three to five years I think the biggest question that is on everyone's minds, that will determine our performance over that period, is really how well we do with mobile."

Shares in California-based Facebook climbed as much as 4.8 per cent as the remarks allayed concerns over the company's ability to generate sales from users who are increasingly socializing over handheld devices.

The stock had plunged 49 per cent since the May 17 IPO amid signs of slowing growth and executives' silence over plans to turn the tide.

"He struck an upbeat tone," said Colin Sebastian, an analyst at Robert W Baird and Co in San Francisco.

"Clearly, from his words, they are making progress in mobile."

Mr Zuckerberg, who appeared at ease while trading laughs with his interviewer, for the first time elaborated on technical struggles that have impeded Facebook from creating a user- and advertiser-friendly mobile application.

The company spent too long trying to build mobile products using a programming language known as HTML5, Mr Zuckerberg said.

"The biggest mistake we've made as a company is betting too much on HTML5," he said.

Facebook is lessening its reliance on the tools, and it has built an application better tailored for Apple's mobile software, Mr Zuckerberg said.

It's also working on an application for Google's Android system.

New features will be available to the mobile service in the coming weeks and months, he said.

Based on the amount of time users spend on mobile, the company should make "a lot more money" via wireless devices than through desktops, Mr Zuckerberg said.

Bloomberg