Users of current-generation Windows Mobile 6 phones can download a new Facebook application starting Thursday.
Microsoft says it's the first application that lets mobile users upload video to their Facebook pages directly from a phone.
Users will also be able to create wall posts, share photos, send messages and update profile pictures from the application.
When the next-generation Windows Mobile 6.5 phones start coming out in the second half, Microsoft will release a Facebook application compatible with the new phones, it said.
In late March, Microsoft announced it would deliver a Facebook app in four to six weeks.
Despite Microsoft's financial stake in Facebook, there has not been an official Facebook application for Windows Mobile phones. BlackBerry devices, iPhones and Palm devices all have Facebook applications.
Also at the end of March, MySpace said it was developing an application for Windows Mobile that would come out in a couple of months. That application has not yet appeared.
While Windows Mobile has traditionally been regarded as a business tool, Microsoft has recently begun adding consumer applications and capabilities aimed at attracting a wider audience to the phones.
The platform may get even more consumer applications with the next-generation Windows Mobile phones, which will feature a new application market.