The Dream handset produced by Taiwan's HTC will run Google's Android open source mobile operating system, and will be sold to work on the US T-Mobile network.
It is expected to be commercially available next month in the US for less than $200 (£120), which will make it competitive against other smartphones, including Apple's iPhone.
To help develop Android, Google formed the Open Handset Alliance, which is a partnership of more than 30 firms aiming to make smartphone software easier to develop.
It is still not known who is branding the device - Google, HTC or T-Mobile. More details will be given at the New York launch later today.