Microsoft just announced a cross-licensing agreement with Samsung. Akin to their patent deals with other Android backers, this one will have Samsung pay per-device royalties for mobile phones and tablets running Android. Microsoft has in total eight cross-licensing agreements with Android backers Acer, General Dynamics Itronix, Onkyo, Velocity Micro, ViewSonic, Wistron, HTC and Samsung.

Microsoft explained in a blog post that the agreement “gives both companies greater patent coverage relating to each other’s technologies, and opens the door to a deeper partnership in the development of new phones for the Windows Phone platform”.

Did the software maker just say that Samsung will focus more on Windows Phone in the future? Per press release, Microsoft and Samsung “agreed to cooperate in the development and marketing of Windows Phone”. Could be just what Microsoft needs given their struggle to keep Nokia afloat. Patent expert Florian Mueller characterized the announcement on his FOSS Patents blog as “the most important Android-related intellectual property deal in its own right”, adding:

Samsung has circa 28,000 patents in the United States and more than 100,000 patents around the world. Curiously, Microsoft hasn’t targeted Apple’s iOS with its patents so far which leads us to believe that Oracle, Microsoft and Apple may be working together to derail Android or at least make it a pricey proposition for handset makers. Be that as it may, it is going to be interesting seeing how this Microsoft-Samsung patent protection affects the nine Apple vs. Samsung lawsuits in twenty countries around the world…

Microsoft last year signed up HTC for patent protection. HTC and Samsung account for more than half of all Android devices sold in the United States. Both are now paying royalties to Microsoft. That leaves Motorola Mobility, with which Microsoft is currently in litigation, as the only major Android smartphone manufacturer in the U.S. without a license. Taiwan-based HTC is paying an estimated $12.50 per-device patent fee to Microsoft. Actually, the Redmond firm makes more money off those Android patent deals than by licensing its Windows Phone software. Check out this paragraph from Microsoft’s blog post by Microsoft’s general counsel Brad Smith and deputy general counsel Horacio Gutierrez:

Cross-posted on 9to5Google.com.