Nokia Windows Phone 7 Lumia 800 4G LTE mobile phone being tested by Verizon and AT&T

America technology news site cnet has learnt that the America mobile phone networks AT&T and Verizon are trialling a 4G LTE version of the Nokia Lumia 800, based on the Microsoft Windows Phone 7 operating system.

Cnet has it that Nokia is making headway with the big two carriers in the U.S, with a network test of a 4G LTE version of the Nokia Lumia 800 smartphone - despite the fact that the Windows Phone OS doesn't yet officially support LTE.

The website notes that the lack of LTE support has been seen as a critical issue for the U.S. carriers, which are increasingly focussing on 4G devices and services.

Nokia has been running a 4G LTE version of the Lumia 800 in an effort to get the ball rolling on carrier approval, according to several people familiar with the situation.

Cnet goes on to state that carriers do test many devices, including some they have no plans to take to market, but Nokia is moving aggressively with the major carriers that bodes well for its prospects in the U.S.

This comes off the back of T-Mobile scheduling a press conference with Nokia on Wednesday, where the announcement is widely expected to be the Lumia 710 - the more budget-friendly, and lower-end, of its two offerings.