Microsoft (NSDQ: MSFT) has decided to sell its 7.3 percent stake in Comcast (NSDQ: CMCSA), according to an SEC filing (via Tech Trader Daily). Microsoft had owned 150,935,575 Class A common stock in cable operator. The decision appears to reflects the bad economy to a small extent. But mostly, it signifies Microsoft’s disinterest in the cable business.

Microsoft began its $1 billion investment in Comcast in June 1997, said Bernstein Research analyst Craig Moffett in an investor note. That was when Microsoft had a short-lived interest in becoming a major player in the cable set-top box business. In May 2007, Comcast stopped using Microsoft’s on-screen program guide for its digital cable boxes in Washington state, the only U.S. location in which that software feature was being used. The cable company, which launched the Microsoft Mediaroom Internet Protocol television (IPTV) platform (formerly Microsoft TV Foundation Edition service) in Nov. 2004, instead began employing the programming software listing it developed with Gemstar-TV Guide called GuideWorks. These days, Microsoft’s only major U.S. TV software client is *AT&T*. It also has some smaller deals in the Latin American, European and Chinese cable markets.

• Microsoft Invests in Heavily-Backed HD Online Video Service Move Networks
• Comcast Drops Microsoft-Powered Programming Guide