Microsoft has lost yet another top ad sales executive.
Rick Song, who spent the past six and a half years at Microsoft, has been named evp of digital sales for Clear Channel Media and Entertainment.
Song most recently was the gm of Microsoft Advertising, often serving as the public face of the company at its annual digital showcase events, during which his team worked to establish MSN as a major entertainment hub  and branded Web video destination. Previously, Song headed up Microsoft’s east coast sales following stints at Yahoo and Forbes.com.
At Clear Channel, Song will focus on cross-platform/integrated media opportunites as well as the radio conglomerate’s budding digital streaming app iHeartRadio . Song’s hire comes just a few months after Google and AOL veteran Tim Castelli was named president of national sales, marketing and partnerships  at Clear Channel.
Said a Microsoft spokesperson: "We have initiated a search for Rick’s replacement. In the interim, John Piontkowski, regional sales director for Microsoft Advertising, will lead our East Coast Region efforts."
Song’s departure is the latest in what could be termed an alarming pattern  at Microsoft. In April came word that both Richard Dunmall, longtime vp of global agencies and accounts, and Marc Bresseel, vp of global marketing, would soon be leaving the company. And over the past year or so Microsoft also lost sales chief Carolyn Everson to Facebook and Jay Sampson, head of emerging media sales, to Machinima.
In addition, Microsoft appears to have scaled back some of its digital ad ambitions of late, as Xbox becomes more of a focal point for the company’s advertising initiatives . There’s word that Microsoft is exploring selling its stake  in MSNBC.com. And the company recently abandoned  its TV Advertising Network.