The world's largest software company, in partnership with phone makers and phone companies such as Samsung Electronics Co Ltd, AT&T Inc and Vodafone Group Plc, said more than 30 new devices with the new Windows Mobile 6.5 software would be on the market in more than 20 countries by the end of the year.
The new phones can play music, open Word and Excel documents, and be synchronized over the Internet.
Microsoft Chief Executive Steve Ballmer played down recent industry talk that the company was developing its own smartphone.
"We are not here to announce today that we are making phones," he said at an event in Paris.
The market for phones is set to treble or quadruple in the next few years, Ballmer said, and Microsoft is ready to challenge other phone makers for market share. He added that Windows Mobile's share of the mobile phone market is equal to Apple's.
"We and Apple are neck and neck and we're chasing the two other players," said Ballmer, referring to Nokia, the world's No. 1 smartphone maker, and Research in Motion.
Microsoft also announced a new online application store, where users can buy 246 applications for their phones.