As forecast in the days prior, Microsoft and Yahoo announced a deal in which Yahoo will incorporate Microsoft's Bing technology as its default search engine, giving the pair almost 30% market share in US searches. (Google holds 65%, comScore reports.)

But even as Yahoo drops search, it will take over pay-per-click search advertising for both companies, granting it access to a broader database through which to target users through its display ad business. 88% of the revenue that appear on its own sites will belong to Yahoo.

Self-serve and search ads will be built via Microsoft adCenter; Yahoo will continue its search affiliate partnerships.

The deal is expected to last for 10 years if approved by federal regulators. The companies said they would implement it two years after such approval is granted.