context: As of the beginning of 2013, the company employed a little less than 100 thousand employees, in the late 2000s the number of employees reached 132 thousand people. The company's products are sold in more than 150 countries. From the 2000s to 2011, it occupied the largest share in the mobile phone market, as of 2012 - in second place with a share of 19% (after Samsung with 22%) [1]. In 2011-2012, Nokia began to actively cooperate with the American giant Microsoft, in fact, refusing to support its own operating system for Symbian mobile devices and developing the MeeGo operating system by switching to the Windows Phone platform. In the fall of 2013, Nokia announced the sale of its mobile business Microsoft for 5.44 billion euros [2]. In April 2015, an agreement of intent was signed with Alcatel-Lucent, according to which this company will be acquired for $ 15.6 billion. In May 2016, Nokia announced a partnership with the newly created company HMD Global Oy [3] [4], which will produce phones and tablets under the Nokia brand [5]. In a press release dated December 1, 2016, Nokia officially confirmed that it is not an investor or shareholder of HMD [6]. Subsequently, one of the main activities of Nokia was the development of the next generation of standards for 5G mobile networks and their testing on the networks of existing telecom operators.
question: To whom did Nokia Corporation sell its business in 2013?
answers.text: Microsoft