During an earnings call today, CBS CEO Les Moonves is reported to have revealed that CBS had turned down an Apple TV service that would rely on advertising revenue.

As reported by GigaOM:

When asked about CBS’s appetite for striking deals with new streaming providers that might not have the money to pay cash upfront to license its content, Moonves said that CBS had decided against joining an Apple TV service because it was based on an ad split.

Apple has been long rumored to be working on some sort of TV subscription service over the past few years. A Wall Street Journal article from December, 2009 described one possible iteration of the service:

The proposed service by the maker of iPhones and iPod music players could, in at least some scenarios, offer access to some TV shows from a selection of major U.S. television networks for a monthly fee, according to people familiar with the discussions.

Such a service, of course, has never launched. But it's not clear if that particular plan was canceled or is awaiting the arrival of a full Apple television.

Rumors of a full blown Apple TV set were recently revived after Steve Jobs' biography quoted Jobs as saying he had "finally cracked" the problems standing in the way of an Apple television set.