PORTLAND, Ore. — Google's Nexus One phone, which goes on sale Tuesday (Jan. 5), has nearly the same form factor as Apple's iPhone.

The new Google phone is made by HTC and is powered by Qualcomm's Snapdragon processor running Google's Android operating system. T-Mobile is Google's designated wireless carrier.

The 3.7-inch capacitive touchscreen uses an organic LED screen with 480 by 800 pixels set within a case measuring 11.5 by 60 by 119 millimeters. The phone has almost identical curved corners and contoured edges as the iPhone. Along its left edge is a volume control and a power button on the top edge with a sleep setting and a headphone jack.

The Nexus One has four keys along its bottom edge for back, menu, home, and search. Its most distinctive feature is a tiny white trackball below the buttons.

A micro-USB port is included, along with a three-element connection for a dock. A 5-megapixel camera with a Xenon flash is located on the back of the phone. Inside, the Nexus One has 512 Mbytes of RAM, 512 Mbytes of ROM, a light sensor, proximity sensor, an accelerometer, a GSM radio, Wi-Fi chip, GPS chip and a microSD slot with a 4-Gbyte card that is expandable to 32 Gbytes.

The unlocked Nexus One sells for $530, or $180 with a 2-year contract with T-Mobile.