Facebook Inc. (Nasdaq: FB), owner of the world’s most popular social-network, is updating its application for Apple Inc.’s iPhone and iPad to make it faster for users who access the service via mobile devices.

The new software aims to double the speed for starting the application and scrolling through the News Feed, according to Mick Johnson, mobile-product manager at Facebook. Speeds also should double for opening photos from News Feed.

Facebook has lost about half its value since an initial public offering in May as the company struggles to generate advertising revenue from the growing slice of users who access the service on mobile devices. More than half of Facebook’s 955 million users visit the site on smartphones and tablets.

“We’re going to be launching a major update,” Johnson said. “It’s focused on one thing: speed.”

Facebook was little changed at $19.44 at the close in New York. The stock has lost 49 percent since it started trading at $38 on May 18.
Last month, the company reported narrower profit margins for the second quarter, in its first earnings release as a public company.

Operating margin, excluding some costs, was 43 percent in the period, down from 53 percent a year earlier. Revenue rose 32 percent, the slowest pace on record.

Advertising Sales

Facebook said in May that advertising sales growth wasn’t keeping pace with user expansion as more members accessed the service with mobile phones. The number of ads delivered in the U.S. in the second quarter decreased 2 percent even as the number of daily users increased 10 percent, Chief Financial Officer David Ebersman said on a conference call.

“Ad impressions continued the recent trend of growing more slowly than users as more of our usage is on mobile devices,” Ebersman said. “This trend is particularly true in markets such as the U.S., where smartphone use is expanding rapidly.”

Facebook has had little time to gain traction in mobile advertising, having just announced its inaugural mobile- advertising platform in February.

The mobile application, which now gets a two-star rating out of five in Apple’s App Store, will receive other improvements, including a single finger swipe for closing photos, Facebook said.