Last October, Yahoo acquired 20 percent of Right Media Inc., creator of the Right Media Exchange, by leading a $45 million second round. Now, the not-unexpected announcement that Yahoo has a deal to buy the 80 percent it doesn’t own. The price tag: approximately $680 million, payable to shareholders in equal amounts of cash and stock. Yahoo will assume Right Media options and equity awards.

SEE ALSO: DoubleClick Sale Likely to Spur Majors Into Action: Analyst

With the move, Yahoo hopes to extend its online ad reach even more on and off the network and to bolster its leadership image. From the prepared statement of Chairman and CEO Terry Semel, under increasing pressure to deliver on promises: “The acquisition of Right Media will further Yahoo’s goal to create the industry’s most open, accessible and vibrant advertising marketplace, which will help democratize the buying and selling of digitally enabled advertising.”

The subtext woven throughout the release: Yahoo as the anti-Google. Susan Decker, the outgoing CFO who now heads the advertising and publisher group, describes it as being in Yahoo’s “strong financial interest to make sure there is a widely adopted, neutral, frictionless exchange that enables publishers and advertisers to benefit from a basket of the best solutions rather than having to accept a single solution from one of the larger players.” Wink, wink. Nudge, nudge.

Back in 2006, Michael Walrath, CEO and founder of Right Media, said of the investment: “It catapults us to a new level of visibility.” Now that visibility shifts as Right Media Exchange, which claims more than 20,000 buyers and sellers trading over 4 billion impressions a day, becomes part of the much larger Yahoo. Redpoint Ventures is among the other investors in the company founded in 2003.

Update:  Yahoo’s plans for Right Media Exchange include increasing its position as a buyer and seller “to increase liquidity” in the exchange. Publishers will be able to bundle their inventory with Yahoos. (You can see where this could fit in with the newspaper consortium expansion.) We should get more details in a conference call scheduled for 11 a.m. eastern.

WSJ: “In the wake of Google’s $3.1 billion deal to acquire online ad services company DoubleClick Inc., announced this month, Yahoo’s Right Media purchase shows how the Internet companies are using significant acquisitions to stake out broader positions in the changing online ad landscape. DoubleClick unveiled plans to open its own ad exchange prior to the announcement of its acquisition.”

NYT: The deal is expected to close in three montha. “By buying Right Media, analysts have said, Yahoo would accelerate its own efforts to sell and broker ads on other sites. Those efforts began taking shape recently, after Yahoo reached agreements to sell ads on eBay and on some 264 newspaper Web sites.”