Windows Live Messenger working with Facebook

Windows Live Messenger is seeing its integration with Facebook chat grow rapidly.

Microsoft announced yesterday in a blog post that close to 18 million people have "connected" Facebook chat to Messenger since August, when it became possible to do so. And those folks have now accumulated more than 2.8 billion minutes of Facebook chat. All told, there have been 440 million chat sessions between Messenger and Facebook in less than six months, Microsoft said.

Microsoft, which owns a small slice of Facebook, became the first instant-messaging provider to allow its users to chat with friends on Facebook from a third-party platform with the launch of the feature in mid-August. Just three months later, Microsoft announced that 1.5 billion minutes of Facebook chatting had taken place with Windows Live Messenger.

Microsoft's Windows Live Messenger app for Facebook currently has in excess of 15.77 million monthly active users. According to third-party app tracking service AppData, the number of daily active users is a little closer to 13 million, making it the No. 3 top app on the social network, third only to Zynga's Cityville and Farmville.

Microsoft doesn't cater only to Facebook users. The company also announced yesterday that connections between Messenger and LinkedIn have doubled since the platform's last update, while MySpace and YouTube connections have grown nearly 50 percent.

Updated at 9:51 a.m. PT to include more details.