The company, besides supporting Windows, is backing a Linux-based variant in partnership with Nokia Corp.

WSJ: Android Emerges as Big Rival to iPad

Even with the backing of multiple smartphone market leaders, Windows Phone has yet to make a significant dent into Android's and iOS's collective market share.

ENGADGET: IDC: Android claims 75 percent of smartphone shipments in Q3, 136 million handsets sold

Nokia is passing up U.S. holiday sales for its Windows Phone handsets in hopes of introducing them with strong operator backing next year.

FORBES: Last Call: Can Nokia Compete With Apple And Android?

After a slow start, the Windows Phone saw its market share rise in October 2011 with the backing of Nokia, one of the largest smartphone makers in the world, which launched a series of Lumia devices powered by Windows phone.

FORBES: Microsoft Hopes to Tango to Higher Smartphone Relevance