As announced earlier this week, Microsoft's purchase of Nokia's Devices and Services division has closed almost four months later than expected.

Redmond is paying about $5 billion for the Nokia division, now named Microsoft Mobile Oy, and some 8,500 design patents. The software giant is also paying another $2 billion for a ten-year license for 30,000 utility patents, with an option to renew the licenses in perpetuity.

Nokia is, however, keeping hold of two factories. Nokia will operate its 7,500-person factory in Chennai, India, on Microsoft's behalf. The Finnish firm is involved in a tax dispute with the Indian government centered around the plant, and Indian authorities have blocked its transfer until the dispute is resolved. Microsoft announced earlier in the week that it would not take ownership of Nokia's South Korean factory.

Even without these factories, Microsoft is still increasing its headcount by some 25,000, for a total of 126,000 employees.

Microsoft is buying the Asha and Lumia brands and will have limited access to the Nokia brand. The company hasn't announced how products will be branded going forward, and it's not clear that the "Microsoft Mobile" name will ever be consumer-facing. Integration of the two companies is expected to take 18 to 24 months. Stephen Elop, former CEO of Nokia, will become executive vice president of Microsoft's Devices Group, which spans not only Microsoft Mobile, but also Xbox, Perceptive Pixel, and Surface.

Nokia, for its part, will continue with three divisions: HERE, which offers mapping and location services; Nokia Solutions and Networks, which builds networking and communications infrastructure; and Advanced Technologies, which develops and licenses technology. Under the terms of the agreement, it's blocked from selling smartphones until 2016.