San Francisco, Jan 6 - Apple Tuesday said that customers had downloaded over 3 billion applications from the company's App Store for the iPhone and iPod Touch.

The announcement of the milestone came as Google was set to launch a rival to Apple's hit smartphone, but Apple CEO Steve Jobs said thepopularity of Apple's product meant that it had little to fear from the competition.

"Three billion applications downloaded in less than 18 months - this is like nothing we've ever seen before," said Jobs in a statement. "The App Store offers iPhone and iPod touch users an experience unlike anything else available on other mobile devices,

and we see no signs of the competition catching up anytime soon."

Indeed, Apple rivals remain far behind the market leader, which boasts iPhone and iPod Touch customers in 77 countries and an App Store covering 20 categories, including games, business, news, sports, health, reference and travel.

Apple further demonstrated its determination to preserve its lead in smartphones, announcing a deal on Tuesday to buy mobile advertising firm Quattro Wireless for $275 million.

Google bought Quattro's larger rival AdMob late last year for $750 million in a deal that it being reviewed by federal antitrust officials. (dpa)