Facebook co-founder departs for new venture

The college roommate who helped Mark Zuckerberg start Facebook is leaving the fast-growing social networking website in a matter of weeks to create a new internet technology firm.

Dustin Moskovitz promises to remain at Facebook at least one more month before setting out to follow "another passion: making companies themselves run better".

"I didn't want to construct efficiencies, I wanted to engineer them," Moskovitz said of his vision for a new startup.

Moskovitz, who helped Zuckerberg start the social networking service in their Harvard University dormitory nearly five years ago, is taking Facebook engineer Justin Rosenstein with him on the new business adventure.

"Whether I work here or not, I'll forever bleed Facebook blue," Moskovitz wrote in a message posted, appropriately enough, on his Facebook profile.

"Our new project is not a replacement for what we build here, but instead both a complement and a compliment, and we have every intention of making it feel like a natural extension of Facebook's product and purpose."

Rosenstein says that he and Moskovitz are setting out to "build an extensible enterprise productivity suite, along with a high-level open-source software development toolkit, built for the Web from the ground up."

Moskovitz said that he expects Facebook to continue doing fine without him and that his departure is merely him pursuing another passion.

"Dustin has always had Facebook's best interests at heart and will always be someone I turn to for advice," Zuckerberg said in an email announcing the move.

Moskovitz is described as a member of Facebook's technical staff on the company website responsible for internal tools and strategy.

"Leaving Facebook makes me sad, but I feel I have to follow my passion on this," Rosenstein said in a message on his Facebook profile.

"I am enormously excited for the company's further success, a destiny I'm confident it will reach regardless of my participation in it."

Founded in February 2004, Facebook is a privately-owned company headquartered in Palo Alto, California.

According to industry tracker Hitwise, Facebook has been closing the gap with market leader MySpace and got 20.5 percent of US social networking visits in August, a 50 percent increase from what it saw a year earlier.