LOS ANGELES (Reuters) - Microsoft Corp kept quiet on Monday ahead of a mystery announcement amid talk it plans to launch its own tablet computer to rival Apple Inc's massively successful iPad. The world's largest software maker is on track to launch its touch-friendly Windows 8 operating system this autumn and industry watchers are speculating that Microsoft will make an own-brand tablet to kickstart demand. Such a device, likely running on chips designed by ARM Holdings Plc, could include all kinds of features from the Microsoft stable, including integration with the top-selling Xbox game console, Skype video calling and the Office suite of applications. Microsoft has long been expected to integrate the Xbox more tightly with its mainstream software. Earlier this month at the E3 game show, Microsoft announced "second screen" software called SmartGlass, which will allow users to beam video from a tablet to a television and turn the tablet into a controller showing data on the game or film being screened. Xbox has been making inroads into the living room recently, away from its hardcore gamer base. Paying subscribers to Xbox Live now get access to streaming content from Netflix, ESPN, HBO, Paramount Pictures, Hulu Plus and others. Microsoft sent out invitations for the event - to be held at Milk Studios in Hollywood at 3.30pm (22:30 GMT) - to media and analysts last week. Since then, it has declined comment. Communications head Frank Shaw has not gone out of his way to play down talk of a Microsoft tablet, but has not confirmed it either. Earlier in the day, Barnes & Noble Inc ruled out its involvement in the announcement after speculation it was building a new Nook electronic book reader with Microsoft, two months after their April agreement to work together on e-books. If Microsoft does launch its own tablet, it would be a departure from its usual focus on software and potentially throw it into direct competition with its closest hardware partners such as Samsung Electronics Co Ltd and Hewlett-Packard Co. It is not the first time such talk has surfaced, as Microsoft looks for a way to make an impact with Windows 8 and put the best product it can in the market to counter Apple's iPad. Sales of tablets are expected to triple in the next two years, topping 180 million a year in 2013, easily outpacing growth in traditional PCs. link.reuters.com/myc88s Rival Google Inc may experiment with a similar approach after buying phone maker Motorola Mobility this year. When it has ventured into hardware, Microsoft has a mixed record. Reporting By Lisa Richwine in Los Angeles and Bill Rigby in Seattle