NEW YORK (CNNMoney) -- Until recently, Googling "President Obama Twitter" would give you a page of search results topped with a smattering of the president's latest tweets.
That feature disappeared Saturday, when a nearly two-year agreement between Google and Twitter to include tweets in search results through a special feed expired.
The deal dated back to late 2009, when the companies struck a pact that would display real-time Twitter results in Google searches.
"We believe that our search results and user experience will greatly benefit from the inclusion of this up-to-the-minute data, and we look forward to having a product that showcases how tweets can make search better in the coming months," Marissa Mayer, then the company's vice president search products, wrote on Google's blog at the time.
Google (GOOG, Fortune 500) and Twitter are saying little about why the deal ended.
"Twitter has been a valuable partner for nearly two years, and we remain open to exploring other collaborations in the future," Google said in a written statement.
"We work with Google in many other ways," Twitter said in an official statement about the deal expiration. The company noted that it continues to provide real-time stream access to Microsoft (MSFT, Fortune 500), Yahoo (YHOO, Fortune 500), NTT Docomo and "dozens of other smaller developers."
One potential catalyst for the Google/Twitter schism: Google's recent launch of Google+, which adds a social-networking powered real-time layer to Google's product network.
Google also took down the standalone Google Realtime search page at http://www.google.com/realtime that it launched last year. That page now returns a 404 error. (A landing page describing the service was still accessible Tuesday afternoon.)
"We've temporarily disabled google.com/realtime. We're exploring how to incorporate our recently launched Google+ project into this functionality going forward," Google said. "Our vision is to have google.com/realtime include Google+ information along with other realtime data from a variety of sources."
Meanwhile, Twitter has been working to improve its own search results. In June, the company launched a new version of Twitter search that delivers more relevant content as well as related photos and images. 
