Redmond, Wash. -- Just two weeks after announcing a billion-dollar deal to acquire parents from AOL, Microsoft said on Monday it has agreed to sell a portion of those patents to social networking giant Facebook for $550 million. The deal includes approximately 650 of the 925 patents Microsoft originally bought from AOL, plus licenses to several more. Microsoft will retain ownership of approximately 275 of the patents. "Today's agreement with Facebook enables us to recoup over half of our costs while achieving our goals from the AOL auction," said Brad Smith, executive vice president and general counsel of Microsoft. Ted Ullyot, general counsel of Facebook, called the deal "another significant step in our ongoing process of building an intellectual property portfolio to protect Facebook's interests over the long term."