DirecTV ended its nine-day blackout of Viacom Inc. channels early Friday morning, but the prospect of more blackouts looms as Fox and CBS are soon to renegotiate their own distribution agreements.

And a central issue in the Viacom-DirecTV dispute—the availability of Viacom shows on the Web and its impact on TV viewership—could recur even more intensely in those negotiations, industry executives said. Both Fox and CBS put many of their shows online.

Precise financial details of the seven-year agreement weren't disclosed. But people familiar with the situation said Viacom won an increase of more than 20% in the fees paid by DirecTV, which previously had totaled around $500 million annually, lifting the amount to above $600 million.