As expected, Nokia will adopt Windows Phone as its primary smartphone strategy in an attempt to save itself from its own burning platform.

The open letter from Nokia CEO Stephen Elop and Microsoft CEO Steve Ballmer says that Nokia and Microsoft will closely collaborate on development, joint marketing initiatives and a shared development roadmap to align on the future evolution of mobile products.

The partnership was announced at an event in London on Friday.

“Today in London, our two companies announced plans for a broad strategic partnership that combines the respective strengths of our companies and builds a new global mobile ecosystem,” the letter reads.

“The partnership increases our scale, which will result in significant benefits for consumers, developers, mobile operators and businesses around the world. We both are incredibly excited about the journey we are on together.”

Here’s a video announcing the deal: