Zuckerberg: Facebook fixing mobile errors

Facebook Inc. chief executive officer Mark Zuckerberg, in his first interview since the company's initial public offering, said he's taking steps to address the missteps that have weighed on shares and made it hard to make money from mobile advertising.

"Now, we are a mobile company," Zuckerberg said in an onstage interview at the TechCrunch Disrupt conference in San Francisco on Tuesday.

"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," Zuckerberg said.

Shares in Menlo Park, Calif.-based Facebook rose in late trading 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 percent since the May 17 IPO amid signs of slowing growth and executives' silence over how they planned to turn the tide.

"He struck an upbeat tone," said Colin Sebastian, an analyst at Robert W. Baird & Co. in San Francisco. "Clearly, from his words, they are making progress in mobile."

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

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

To address the missteps, Facebook is lessening its reliance on those tools, and it has built an application tailored specifically for Apple Inc.'s mobile software, he said. It's also working on an application for Google Inc.'s Android.

The stock extended its after-hours climb after Zuckerberg said Facebook had a team dedicated to strengthening search capabilities. The company is fielding about a billion search queries a day.

"We have a team working on search," he said. "Search engines are really evolving towards giving you a set of answers."

Facebook, whose stock hasn't closed above the $38 IPO price since its first trading day, reported in July that second-quarter sales had increased 32 percent, down from 45 percent in the previous three months.

The share-price performance has been "disappointing" and it "doesn't help" in terms of employee morale, Zuckerberg said in the interview with Michael Arrington, a venture capitalist and technology-industry blogger.

Earlier in the day, Facebook's stock had climbed 3.3 percent, to $19.43 at the close in New York.