A deal that would have licensed CBS content to YouTube, as well as given Google a piece of CBS's radio network advertising, appears to have unraveled because the two parties have been unable to come to terms.

The proposed deal appeared to be close to becoming reality, with the length of the partnership being the major hurdle that apparently couldn't be cleared, CNET reports. E-Commerce Times adds that Google was promising CBS $500 million in new ad revenue from the deal.

If the deal falls through, CBS would be the second major media company that has backed out of a deal with the video-sharing site in a matter of days.

Earlier this week, Viacom struck a deal with online TV platform Joost to distribute content over the service, after having attempted to reach a similar deal with YouTube.