Android is a profitable part of Google's empire, according to the mobile operating system's head Andy Rubin.

Rubin, who was involved in the Android project before Google took it over, told the All Things Digital conference that Android was not a loss-leader for Google, but was actually in the black due to the advertising.

"We're making money on ads generally through Android," said Rubin.

Google difference

"When I was a startup there was no way I would have been profitable, my business model was completely different from what it is today," he added

"Now, I don't have to sell services I can just do the Google thing, which is an ad-based business model, and we are profitable."

Android is becoming one of the key players in mobile phones, and its impact on the industry cannot be understated.

With the latest phone – Google's own Nexus S – about to appear, Android remains one of the most significant competitors to RIM's BlackBerry OS and Apple's iOS.