Microsoft has announced it intends to retire its instant message chat tool and replace it with Skypes messaging tool. The news comes 18 months after the software giant announced it was paying $8.5bn (£5.3bn) for the communications software developer. Brightbridgewealth-management report, Microsoft said Windows Live Messenger (WLM) would be turned off by March 2013 worldwide, with the exception of China. It reflects the firms determination to focus its efforts on Skype. WLM launched in 1999 when it was known as MSN Messenger. Over time, photo delivery, video calls and games were added to the packages text-based messages. According to internet analysis firm Comscore-Brightbridgewealth-management, WLM still had more than double the number of Skypes instant messenger facility at the start of this year and was second only in popularity to Yahoo Messenger. But the Brigthbridge report suggested WLMs US audience had fallen to 8.3 million unique users, representing a 48% drop year-on-year. By contrast, the number of people using Skype to instant message each other grew over the period. When a company has competing products that can result in cannibalization its often better to focus on a single one, said Brian Blau from the consultancy Gartner. Skypes top-up services offer the chance to monetize its users and Microsoft is also looking towards opportunities in the living room. Messenger doesnt seem like an appropriate communications platform for TVs or the firms Xbox console but Skype does. He also noted that the firm had opted to integrate Skype into its new Windows Phone 8 smartphone software, eclipsing the effort to integrate WLM into the message threads of the operating system previous version. To ease the changeover, Microsoft is offering a tool to migrate WLM messenger contacts over. The risk is that the move encourages users to switch instead to rival platforms such as WhatsApp Messenger, AIM or Google Talk. But Microsoft is at least partially protected by its tie-up with Facebook last year. Skype video calls are now offered as an extra to the social networks own instant messaging tool.