Discovery’s US nets delivered a 5% increase in 2Q rev to $516mln, powered by "growth in distribution and advertising revenue at most channels." Excluding the loss of Travel Channel rev effective May 14, the nets’ ad rev rose 12% thanks to greater audience delivery on Discovery Channel and TLC, among others. Prime ratings for the pair grew 7% and 11% in the Q, respectively, among adults 25-54. — News Corp’s cable net programming saw 4Q07 operating income increase 46% to $284mln, reflecting greater contributions from Fox News, RSNs, FX and Fox Intl Channels. Fox News’ 41% operating income growth came from higher affil rates and ad rev. Op income at the other nets rose 48%. — Liberty Media’s set to get even more complicated. It plans to create a 3rd tracking stock by splitting Liberty Capital into 2 separate tracking stocks. The newly created Liberty Entertainment stock will hold the 38.5% DirecTV stake it will receive from News Corp following expected regulatory approval, as well as the 3 RSNs and $588mln it expects to acquire in the transaction. Liberty’s interest in Liberty Ent Group—Starz, GSN, WildBlue, FUN Technologies—and $550mln of Liberty Media’s publicly traded exchangeable debt will also go into the new stock. Liberty Capital’s 2Q operating income fell to $42mln from $44mln. Fellow tracking stock Liberty Interactive saw operating income rise 1% to $244mln.