Tuesday's move came a day after both shows resumed new episodes following a two-week hiatus. The blockade had affected all online viewers, not just DirecTV subscribers.
Stewart ripped the Comedy Central network owner in a segment that aired Monday night, saying: "You're pulling shows from the Internet? Viacom, what are you, China?"
Since last Wednesday, some 20 million DirecTV customers have been without Viacom channels like MTV, Comedy Central and Nickelodeon while the companies haggle over how much DirecTV should pay to carry those channels.
Viacom says it hopes the restoration of those shows online is helpful to its fans who subscribe to DirecTV and "who have yet to switch" to a provider that carries its networks.
DirecTV Group Inc. responded in a statement: "We're glad they decided to do the right thing, not just for DirecTV customers, but for all fans" of the shows.
Viacom Inc. says thousands of full episodes are still available online for free, but the blockade is still up for some shows, including new episodes of MTV's "Teen Mom."
Both sides say they continue to negotiate on the terms of a new deal.
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