The “for sale” sign has officially been hung on TV Guide Channel.

Macrovision, the Santa Clara, Calif.-based tech company that bought Gemstar-TV Guide Intl. in May, has sent out the preliminary briefing books on the cabler to prospective bidders.

The channel is distribbed in more than 80 million cable/satellite TV homes, but it is expected to fetch a fire-sale price of only around $400 million because of the broader turmoil in the financial markets and because of specific issues with the cabler. (By way of comparison, the Weather Channel fetched $3.5 billion from NBC Universal and its private equity partners in July.)

A number of TV Guide Channel’s carriage agreements give cable operators the discretion to move the channel into a digital tier, which could significantly shrink its subscriber base. Its contracts also tend to include low subscriber fees from cable ops, making the channel more dependent on advertising sales for its profitability than most basic cablers. TV Guide Channel’s ad sales hit $129 million last year, according to Gemstar-TV Guide’s annual report for 2007.

Among the entities kicking the tires on TV Guide Channel is Constellation Ventures, the Gotham-based venture capital fund whose active media investments include music Netco ArtistDirect and the fledgling TV One cabler targeting African-American auds. The channel is not generating any heat among showbiz’s usual suspects for cable properties, such as Time Warner, News Corp. and Disney.

Macrovision, which signaled its intent to sell off the channel when it closed its acquisition in May, has told bidders it hopes to have a sale agreement in hand by the time it reports its third-quarter earnings in early November. A company spokeswoman declined comment Monday on the TV Guide Channel sale.