As the new year approaches, some U.S. cable subscribers could see Tribune Broadcasting Co. LLC- and Nexstar Media Group Inc.-owned TV stations go dark.

Tribune Media Co.'s Tribune Broadcasting said its contract with Charter Communications Inc. expires at midnight ET Jan. 1, 2019, after which 33 local television stations and cable network WGN America (US) may be unavailable to Charter's Spectrum TV customers unless a new agreement is struck. Similarly, Telephone and Data Systems Inc.'s TDS Telecom warned its subscribers that Nexstar Media Group Inc.-owned stations may be unavailable after Dec. 31, 2018, if the companies are not able to reach a new agreement.

TDS Telecom said in different blog posts aimed at various regional subscribers that the contract expiration could mean the loss of programming of local stations affiliated with major broadcasters, including ABC (US), CBS (US), FOX (US) and The CW (US). The stations impacted are in Colorado, Indiana, Nevada, New Mexico, Oregon, Tennessee, Texas and Utah.

In the Dec. 21 blog posts, TDS Telecom said it and Nexstar remained at odds over pricing and other contract terms.

Representatives of Nexstar and Charter did not immediately respond to requests for comment.

The Tribune and Nexstar deals are among a flurry of TV agreements set to expire by Jan. 1. Walt Disney Co. also is airing ads on some of its networks warning Verizon Communications Inc.'s Fios customers that the networks could go dark if Verizon and Disney cannot strike a new agreement by 5 p.m. on New Year's Day.

Nexstar and Tribune Media are seeking to merge in a $6.4 billion deal struck Nov. 30.