Users will not be able to use Beluga to send messages after Nov. 11, and the service will be shut down completely on Dec. 15.

For now, users can access their old messages via the Beluga app and website, and download of their private messaging groups, or "pods."

"We'd like to thank you all for being such enthusiastic and loyal users. We'll continue to use your feedback to improve Messenger and make messaging your friends easier, faster and more fun," reads a posted on the Beluga website on Friday.

Facebook acquired Beluga's technology and staff in March. Facebook Messenger was launched in August and is available in 22 languages, for iOS, BlackBerry and Android devices.

Mobile is an increasingly popular way of accessing and using Facebook, and more than 350 million users access the service from a mobile device, according to the company.