Viacom said it had made a series of offers for a deal with Charter but could not meet the conditions asked by Charter.
"While we`re making every effort to reach a new deal, Charter`s actions may force a disruption in Spectrum subscribers` service," Viacom said in a statement.
The current deal between Charter and Viacom expires Oct. 15, according to a person familiar with the situation who declined to be identified. A blackout would hit 16.5 million subscribers.
A spokesman for Charter declined to comment.
Earlier this year, Charter moved Viacom`s flagship networks to its most expensive programming tier, a move that threatened the media company`s affiliate and advertising revenue.
This marks the first major affiliate dispute for Viacom since CEO Bob Bakish took over last year. Bakish has made it a priority to improve relations with distributors.
Viacom is in the midst of a turnaround plan to improve ratings and ad revenue.
Like many of its peers, Viacom is struggling to keep viewers as more watch on smartphones and tablets. Six of the largest U.S pay TV providers posted subscriber losses during the past quarter.
Shares of Viacom were marginally down in extended trading, while Charter shares were unaffected.
(This article has not been edited by Zeebiz editorial team and is auto-generated from an agency feed.)