The new user interface of Windows Phone 7.8 will be inspired by that of Windows Phone 8. (All rights reserved) Nokia developing Windows RT tablet: rumour Lumia sell-out no proof of Nokia turnaround Is Nokia about to start developing Android handsets? Nokia Siemens to close German plant RIM loses patent dispute with Nokia

According to several major American tech sites, Nokia has reportedly released on its servers Microsoft's 7.8 update of its operating system, allowing the older generation of Lumia phones to access the same user interface and certain functions and themes as the Windows Phone 8.

The first Lumia models in line to run the OS are the 510, 610, 710, 800 and 900.

First announced in November, its launch was officially delayed to 2013. At the same time, a string of new smartphones using Windows Phone 7.8 will become available, at a lower price point than Windows Phone 8 devices.