Cyanogen, which is developing a version of Android independent to Google, is set to close a Microsoft-backed round that would value it in the nine figures.

Cyanogen, the US-based developer of an operating system for mobile devices, is raising a $70m series C round featuring software producer Microsoft, the Wall Street Journal reported yesterday.

Kirt McMaster, Cyanogen’s chief executive, hinted at the funding at an event last week when he mentioned that the company has raised $100m, up from the $30m so far publicly disclosed.

Cyanogen is working on an open source operating system for the Android mobile platform called CyanogenMod, which would be free of…