Shares of AOL (NYSE: AOL), the seventh-most-visited website, jumped nearly 50 percent Monday after announcing a $1.1 billion patent deal with Microsoft.

After opening up 35 percent, the shares rose as much as 49 percent and stayed up all day, before closing up $7.98 at $26.40, a 43 percent jump. The latest jolt brings their total gain for 2012 to 75 percent.

AOL has been under pressure from activist investor Starboard Value, a hedge fund, to drive better financial results. Last month, the company's stock rose 7 percent in a day when patent sales or auctions were first mentioned by AOL CEO Tim Armstrong.

Terms of the agreement include outright sale of 800 patents to Microsoft, the world's top software developer, as well as grant of a non-exclusive license to the remainder of the its patent portfolio and applications.

Microsoft, in Redmond, Wash., operates the Bing search engine, MSN network and e-mail services and other applications that compete with AOL.

In a statement, Microsoft general counsel Brad Smith, said This is a valuable portfolio that we have been following for years and analyzing in detail for several months. Micrrosoft shares fell 42 cents to $31.10. Microsoft's purchase came in advance of the closing of Google's $12.5 billion acquisition of Motorola Mobility Holdings (NYSE: MMI). That deal will challenge Microsoft on the desktop as well as on mobile electronics.

AOL's auction of the patents was handled by Evercore Partners (NYSE: EVR) and Goldman Sachs (NYSE: GS), with legal advice from Wachtell, Lipton, Rosen & Katz and Finnegan, Henderson, Farabow, Garrett & Dunner.

The online service still will continue to retain rights to an additional 300 patents, which aren't covered by the deal.

In an interview last month, Paul R. Ryan, CEO of Acacia Research (Nasdaq: ACTG), an investment bank specializing in intellectual property, suggested this sale could realize hundreds of millions for AOL, but was not a panacea.Acacia had analyzed the AOL portfolio, he said.

Ryan credited Starboard Value, which now controls 5.2 percent of AOL, with spurring the AOL patent auction.