Microsoft, which recently agreed to pay $1 billion for a portfolio of patents from AOL, today said it will sell a portion of those patents to Facebook for $550 million in cash.

The company noted that the AOL deal included the rights to 925 patents and applications, plus a license to 300 more AOL patents that were not for sale.

Facebook will now take ownership of 650 of those AOL patents and applications, and it will get a license to the AOL patents that Microsoft will keep for itself. On close of the deal, Microsoft will keep 275 AOL patents and applications; it will have a license to the patents Facebook is buying; and it will still have a license to the 300 patents AOL decided to keep.

“Today’s agreement with Facebook enables us to recoup over half of our costs while achieving our goals from the AOL auction,” Microsoft general counsel Brad Smith said in a statement. “As we said earlier this month, we had submitted the winning AOL bid in order to obtain a durable license to the full AOL portfolio and ownership of certain patents that complement our existing portfolio.”

Facebook general counsel Ted Ullyot said that the deal is “another significant step in our ongoing process of building an intellectual property portfolio to protect Facebook’s interests over the long term.”

The companies said that are still “evaluating the accounting treatment for these transactions.”