Quadrangle Group, the big media PE firm, has added former Yahoo (Nasdaq: YHOO) COO Dan Rosensweig to the firm and he will open up a Silicon Valley office for the company. Would be interesting to see what Rosensweig looks at for investment/buyout, besides working with existing portfolio companies. Prior to Yahoo, Rosensweig was President of CNET Networks…they could use some PE help right about now.

Also added: Edward Sippel, who will open up a Hong Kong office for the firm. Sippel previously served as Partner and Managing Director at TVG Capital Partners, where he focused on PE investments in the technology, media and telecom sector in the Asian markets. More in release.

PEHub: Quadrangle founder Steve Rattner in a short interview: “We are not going to begin investing in early-stage companies. But we do believe that new media companies are becoming more mature and, therefore, not early-stage anymore. For example, we just took public a new media company called Dice. It happens to be based in New York, but we would have been happy to invest had it been in Silicon Valley.”

Note:  is speaking at our Future of Business Media conference in October.