Facebook announced a deal worth one billion dollars (760 million euros) on Monday to buy the business behind smartphone photo application Instagram.

The purchase was seen by some as a move to strengthen Facebook's standing against competitors such as Google Plus in the weeks leading up to its much anticipated stock market debut.

Announcing the deal, Facebook co-founder Mark Zuckerberg called it "an important milestone for Facebook because it's the first time we've ever acquired a product and company with so many users."

Zuckerberg added that such deals would not lay the basis for his company's future business model. "We don't plan on doing many more of these, if any at all," he said.

The scale of the deal is being seen as unprecedented for the purchase of a company with relatively little in the way of revenue streams.

San Francisco-based Instagram's application for Apple iPhones, iPads, and iPod touch devices has been downloaded more than 30 million times since its first release in late 2010.

A version for Google-backed Android software attracted more than a million users within 24 hours when it was released last week.

The free program allows users to add effects to photos using "filters" and then share them via Twitter, Facebook and other social networks. Apple named Instagram as its "App of the Year" for 2011.

rc/slk (AFP, dpa, Reuters)