The deal, announced by Microsoft in a blog post, means that data from Britannica Online will be added to selected Bing search results.
It is part of Britannica's expansion into digital, following an announcement in March that it would cease production of its print edition after 244 years.
But the move is also viewed as Microsoft's response to the Knowledge Graph on search rival Google, which consolidates information on certain subjects around search results.
Microsoft already offers an 'answers' feature on Bing, which gives a "snippet of information" alongside search results, as well as options to "dig deeper into the results".
"The answer provides a quick overview of the subject, a thumbnail image, and useful facts and figures making it easier than ever to get trusted content in search. We also pull in direct links to other trusted sources," he said.
"We're very excited to collaborate with Encyclopaedia Britannica as it continues to strengthen its online presence, and hope you find these new answers valuable and helpful in your search for information."
Alongside the Britannica Online results, Bing search results will also flag up other sources of information, including Wikipedia, Qwiki and Freebase.
Launched in mid-May, Google's Knowledge Graph is designed to make web searches "more human", by providing more relevant results and information.
The Knowledge Graph provides responses based on Google's information bank containing more than 500 million objects and 3.5 billion facts.