Microsoft bought Aquantive for $6.3bn in cash in an attempt to catch rival Google in the race to increase revenues from search-related advertising.
The "write down" will probably wipe out Q 4 profits..
In addition to the writedown, Microsoft said its forecast for future growth and profitability at its online services arm - which includes the Bing search engine and MSN internet portal - were "lower than previous estimates".
@frank, its not so much that the right down was itself expected, but it is not significant news: its recognises that MS paid far too much for Aquantive, which is something that everyone who follows MS would have known by now.
Also, this is just an accounting number, and does not tell you anything about cash flows, which are what ultimately matter to investors.