BERLIN — Microsoft, taking aim at the world’s fastest-growing smartphone market, said on Monday that it would team up with Huawei of China to sell a low-cost Windows smartphone in Africa.

The phone, called the Huawei 4Afrika Windows Phone, will cost $150 and initially be sold in seven countries. Microsoft’s Windows Phone software is fourth among smartphone operating systems, with just 2 percent of the worldwide market in September, according to Canalys, a research firm in Reading, England.

“Microsoft is a small player in smartphones and it needs as many partners as it can get,” said Pete Cunningham, an analyst at Canalys. “And Africa is one of Huawei’s strongest markets outside of China.”

Microsoft’s choice of Huawei, a leading maker of mobile networking equipment for African operators, does not detract from Microsoft’s commitment to Nokia, which is relying on Windows Phone software to lift its new line of smartphones and return the company to profitability.