Apple announced the third version of its iPad tablet computer which includes LTE connectivity and Apple’s most advanced Retina display technology yet, featuring “quad-core graphics.”

The new iPad will initially be available for the LTE networks of the two largest US operators in terms of connections, Verizon Wireless and AT&T. US number three Sprint has yet to sign up to offer the device. Wi-Fi-only versions will also be available.

The device uses Apple’s A5X processor with what the company calls “quad-core graphics" to support the high-definition Retina display. The A5X provides double the graphics performance of the iPad2’s A5. The display has 3.1 million pixels, four times the number of pixels seen on the iPad2.

Like its predecessor, the new iPad has a 10 hour battery life and a 5MP camera capable of 1080p HD video, with the addition of video image stabilisation.

The new iPad will be available in black or white in selected markets from 16 March, starting at US$499 for the 16GB Wi-Fi only version, rising to US$829 for the 64GB LTE model. Customers can pre-order the latest iPad from today. The iPad2 has been reduced to a starting price of US$399.

The latest iPad also heralds the arrival of the iOS 5.1 update which includes Personal Hotspot technology that allows iPad users to share their network connection with up to five other devices via Wi-Fi, Bluetooth or USB. It also includes voice dictation which can also be used with third-party apps such as Facebook or Twitter.