The launch of the "Galaxy Nexus", which comes days a after the new iPhone 4S went on sale, was initially scheduled for October 11 but was delayed following the death of Apple chief Steve Jobs as a gesture of respect.
Samsung -- the world's number two mobile phone maker -- and Apple are also engaged in a series of patent lawsuits over the technology and design of smartphones and tablet computers.
"We are very proud of this milestone," Samsung's Mobile Communications Business president JK Shin said as the new phone was unveiled in Hong Kong.
The Galaxy Nexus is the first device to use the new Android "Ice Cream Sandwich" -- a title that continues Google's tradition of naming its operating systems after desserts in alphabetical order.
The firms said the new handset offers easier and quicker Internet browsing, an improved camera and enhanced security using face recognition technology.
It also features "Android Beam", a function that allows content to be shared between two devices by s