[UPDATED] Microsoft and Samsung, the world’s No. 2 smartphone maker behind Apple, just announced a patent licensing agreement that gives Samsung legal coverage for its use of Google’s Android operating system in its smartphones.

Under the deal, Microsoft says it will receive unspecified royalties for every Android device that Samsung sells. The agreement covers both mobile phones and tablets, according to the Redmond company.

“Together with the license agreement signed last year with HTC, today’s agreement with Samsung means that the top two Android handset manufacturers in the United States have now acquired licenses to Microsoft’s patent portfolio,” write Microsoft general counsel Brad Smith and deputy general counsel Horacio Gutierrez in a blog post. “These two companies together accounted for more than half of all Android phones sold in the U.S. over the past year. 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.”

Google is currently in the process of acquiring Motorola for $12.5 billion.

Microsoft’s Samsung deal is a major development in the technology patent wars, and a boost for Microsoft’s claims that Android violates its intellectual property. Samsung has separately shown no sign of backing down in its dispute with Apple over the iPhone maker’s Android patent claims.

Google isn’t directly involved in the disputes but its chief legal officer, David Drummond, spoke out in August against what he called “a hostile, organized campaign against Android by Microsoft, Oracle, Apple and other companies, waged through bogus patents.”

Smith and Gutierrez address Google directly in their post: “We recognize that some businesses and commentators – Google chief among them – have complained about the potential impact of patents on Android and software innovation,” they write. “To them, we say this: look at today’s announcement. If industry leaders such as Samsung and HTC can enter into these agreements, doesn’t this provide a clear path forward?”

Specific financial terms of the Samsung deal weren’t disclosed. As noted by Microsoft, it previously struck a similar patent deal with HTC, in which the Redmond company is reportedly receiving $5 for every Android handset that HTC sells.

Perhaps not coincidentally, both Samsung and HTC make devices that run Microsoft’s Windows Phone operating system. The Microsoft lawyers say in the post that the latest deal gives Microsoft and Samsung “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.”

Microsoft says in the official news release that the new cooperation with Samsung will also include marketing Windows Phone. Microsoft started to roll out the Windows Phone “Mango” update yesterday, a key test for its mobile initiatives.

Follow-up: Will Microsoft get patent royalties from Amazon’s Kindle Fire?