Windows Phone is reportedly up for a new major redesign with the next version currently under works, aiming to unify smartphone and tablet platforms.

Microsoft's Windows Phone platform made its debut nearly three years ago, but it still has a long way to go before achieving the whopping success the company likely hoped for.

Despite its best efforts, Microsoft's mobile market share is still low, struggling in the single digits. The company boasted a major OS redesign from Windows Phone 7 to Windows Phone 8, but not even this effort was able to significantly boost sales. Microsoft's pure ARM tablet operating system (OS), meanwhile, proved even less successful.

According to Eldar Murtazin of Mobile-Review, Microsoft decided to go back to the drawing board and work on the next version of its Windows mobile OS. The company reportedly has a working group dedicated to developing a blueprint for the next Windows Phone version. The platform will allegedly be redesigned from the ground up, yet again.

Microsoft has apparently charged the group with developing a new single OS for both smartphones and tablets, and nothing is off-limits in terms of changes. That includes the Metro user interface (UI), which may either sport a major redesign in Windows (Phone) 9, or be scrapped altogether and replaced with something else.

"The increase in the life cycle of Windows Phone from 18 to 36 months (user support) means that the new version of the newly developed almost from scratch," reads a rough translation of Murtazin's report. "And yes, I can say with accuracy that once again we will be offered a different version of UI (Metro UI will not be able to admit a mistake, it is too actively advertised, but the next version will probably be different.)"

"At the moment, the new interface does not exist, as well as the demands generated by the OS, but it is certain that the first time Microsoft will try to create a system that will operate on smartphones and tablets," adds the report. "The Working Group, which is looking into the matter, must form an opinion by this fall, presumably the completion of the project will take place in 2015."

Merging Windows RT and Windows Phone into a single operating system may give Microsoft the traction it needs. The Metro UI gained some critical praise, but Microsoft failed nonetheless in boosting customer interest. The Windows Phone platform has also seen a boost, especially with recent Nokia flagships, but it lags far behind its Android and iOS rivals. It remains to be seen whether a completely redesigned Windows (Phone) 9 will turn things around.