Maintaining Windows Live Messenger made less sense after Microsoft Corp. bought Skype for $8.5 billion last year. A new version of Skype released a few weeks ago allows users to sign in with a Microsoft account. By merging the two services, people won't have to maintain two separate contact lists.
Microsoft says much has changed in how people communicate. There's more use of text messaging and social networking, for instance.
Microsoft said in Tuesday's announcement that Messenger users who switch to Skype will get benefits such as the ability to call landline and mobile phones and better support on mobile devices.
Except for mainland China, Messenger will be discontinued worldwide after the first quarter of 2013.