For the new offensive to gain market share, Nokia just announced its new flagship, the Lumia 900 powered by Microsoft Windows Phone OS.  The phone will be available exclusively on AT&T network with 4G LTE support. The new 4G LTE can transfer data up to 50Mbps where it is available.

The phone features 4.3-inch AMOLED ClearBlack display at 800 by 480 pixels. The device is using  polycarbonate casing in cyan blue or black color; 8-MP rear camera equipped with Carl Zeiss lens plus dual LED flash. The lens sports f2.2/28mm aperture for better low-light shots. The camera supports video capture at 720p/30fps. There’s a second, front-facing camera for video chat, the front camera is a 1-MP with an f2.4 lens and 30fps capture. Video chat Tango app comes bundled with the device.

Windows Phone Mango OS will drive the  1.4GHz Qualcomm Snapdragon APQ8055 + MDM9200 CPU. . The souped-up 1840mAH battery in the Nokia Lumia 900 will last for about 7hrs talk-time and up to 300hrs on standby.

The latest iteration of Windows Phone will be added  Nokia Maps and Nokia Drive through the Windows Phone Marketplace. Nokia Drive offers free, turn-by-turn, voice-guided navigation everywhere.

No word yet on availability or pricing.

Specs

• Networks: GSM/EGSM 850/900/1800/1900, WCDMA 850/1900/2100, LTE Band 4 (1700/2100) & 17 (700)
• OS: Windows Phone Release 7.5 – Mango Commercial Release 2 (Mango + LTE)
• Memory: 512MB RAM
• Storage: 16 GB internal memory (14.5GB user memory) + SkyDrive cloud storage
• Volume: 90cc
• Weight: 160g (5.6 ounces)
• Dimensions: (max): 127.8 x 68.5 x 11.5 mm (5 x 2.7 x .45 inches)
• A-GPS
• Wi-Fi (802.11 b/g/n)
• USB 2.0 high-speed
• Bluetooth 2.1 + EDR
• 3mm headset connector