AT&T's HBO and Cinemax programs were pulled from Dish Network's satellite-TV service after the two companies failed to reach a new distribution agreement.
It is the first time in HBO's 40-year history that programming has been blocked at a distribution partner over a contract dispute, according to AT&T, which acquired the premium network as part of its June $85 billion acquisition of Time Warner.
Dish said the channels went dark at midnight Wednesday for its customers and subscribers of its Sling TV online service. The dispute is over demands by AT&T's WarnerMedia that Dish pay for a guaranteed number of subscribers, regardless of how many consumers actually subscribe to HBO, Dish said.
Dish made the move as the U.S. Justice Department is trying to appeal a federal court ruling that allowed AT&T, the largest TV service provider to purchase Time Warner, which was renamed WarnerMedia after the deal.
Dish has been particularly aggressive lately in negotiations with programmers. Spanish-language network Univision has not been carried on Dish for several months, costing both companies millions in subscriber fees.
"Past behavior shows that removing services from their customers is becoming all too common a negotiating tactic for them," HBO said in a statement.
Dish, which has 13 million subscribers, says the blackout is a sign that media consolidation will put more pricing pressure on TV distributors.
"Plain and simple, the merger created for AT&T immense power over consumers," Andy LeCuyer, Dish's senior vice president of programming, said in a statement.