A match made in pinstripe

Microsoft and Yahoo are expected to seal and internet search partnership later today, concluding a year and a half of torrid courting, according to people familiar with the matter (via The Wall Street Journal).

Microsoft made an unsolicited, and unsuccessful, $47.5 billion bid for Yahoo in February 2008. A consolidation of both search strengths would result in immediate co-ownership of over 20% of the search marketplace — a potentially formidable contender against search leader Google, which hosts over 70% of US searches, per StatCounter. (comScore pegs Google's search share as slightly less, closer to 65%, and Yahoo's share as higher, almost 20%, meaning a "MicroHoo" combination could actually result in consolidation of 30% of search share.)

Users are not expected to notice a dramatic difference between Yahoo and Microsoft sites following the deal, and Yahoo will continue to operate sales of its own pay-per-click ads — the sponsored text-based messages that appear in search results. It may also take responsibility for ad sales across some Microsoft properties.

The deal is expected to be a revenue-share with no up-front payments. But antitrust concerns raised by the Department of Justice will likely determine its final structure, Advertising Age points out.

Last November Yahoo and Google scrapped a planned search deal midway through the DoJ's antitrust violations screening.