The deal is to be unveiled by Kevin Turner, Microsoft's chief operating officer, and Ann Livermore, an executive vice president at HP, at an afternoon event. The companies put out a media alert on Tuesday saying that the pair would announce "an enterprise agreement between the companies."
A Microsoft representative declined to offer more details, though the deal is expected to cover services, as, is among those expected to speak at the event.
HP and Microsoft have historically had close ties. In the consumer arena, HP was among the early partners for Microsoft's Media Center PC effort and has also joined forces with the software giant on many other emerging technologies. A representative for HP was not immediately able to comment.
CNET News.com's Tom Krazit contributed to this story.