Microsoft and Yahoo have been joined at the hip since 2009, when Yahoo announced a 10-year agreement to use Microsoft's Bing search engine. A related contract got Microsoft to guarantees Yahoo’s revenue per search for the first 18 months. Microsoft renewed that agreement with Yahoo in the fourth quarter of 2011, but only for the markets of the U.S. and Canada. That agreement actually expired March 31, 2013
Today, Yahoo revealed as part of a filing with the U.S. Securities and Exchange Commission that the company has extended its search revenue guarantee with Microsoft, but apparently this new deal is just for the U.S. market. The deal was made retroactive to April 1, 2013 and will continue until March 31, 2014. Yahoo added, "We are currently unable to estimate what impact, if any, the extension of the RPS Guarantee will have on our future financial results."
As far as the main search engine agreement with Microsoft, Yahoo stated in the SEC filing that the transition to using Bing has now been completed in the U.S., Canada, most of Europe, India, and six countries in Latin America. It added:
We are continuing to work with Microsoft on transitioning paid search in the remaining markets. The market-by-market transition of our paid search platform to Microsoft’s platform and the migration of paid search advertisers and publishers to Microsoft’s platform are expected to continue through 2013, and possibly into 2014.
Recently, Yahoo CEO Marissa Mayer claimed that the company has yet to see much of a benefit from its search engine deal with Microsoft but there's been no indications that Yahoo plans to make any major changes to the deal anytime soon.
Source: SEC | Image via Yahoo