Deal with Xiaomi opens window for Microsoft

Microsoft Corp said on Wednesday that it has joined forces with Xiaomi Corp, making the soon-to-be-released Windows 10 operating system potentially available to millions of smartphones produced by the red-hot Chinese handset maker.

The Redmond, Washington-based software giant said that "a select group of Mi 4 power users" will be invited to test Windows 10 for its official release later this year. The Mi 4 is a flagship handset launched by Xiaomi in 2014.

The handset maker is an unlikely partner for Microsoft. It has been known as an Android phone producer that tailors Google Inc's mobile OS for Chinese customers.