Microsoft risks cannibalizing its most profitable business in doing so, says Reuters. The Redmond, Wash.-based business software division, which includes Office, made $9.3 billion in profit from $14.3 billion in sales during the first three quarters of its 2009 fiscal year. The announcement is the latest tit-for-tat in an increasingly intense rivalry between Microsoft and Google. The Mountain View, Calif., search giant last week said it would develop an operating system designed to lure users from personal computers, Microsoft's home turf, to using applications on the Internet, where Google has a dominant presence. Dubbed Chrome OS, the software would be made available to the open-source community, which implies that it would be free, unlike Microsoft's Windows operating system, which powers more than 90 percent of the world's computers. 