More than 6 million customers of Charter Communications’ Spectrum pay-TV service are swept up in the latest fee dispute between the cable TV company and Tribune Media.

Charter Communications and Tribune Media, which carries WGN America programming, have spent nearly two weeks in a standoff over Tribune Media’s proposed fee increase for programming it provides for Spectrum pay-TV packages. The companies failed to reach an agreement on a new distribution deal by Jan. 2, leading to a blackout of WGN channels.

Locally, WGN carries shows such as “Last Man Standing,” “Blue Bloods” and “In the Heat of the Night.”

The number of households affected in Maine is unknown because Charter does not reveal details of its customer base. Municipal officials, however, received letters from Spectrum notifying them of the blackout of WGN shows in their communities.

As of 5 p.m. Wednesday, “Spectrum’s agreement to carry Tribune’s channels expired. As a result, WGN America and all associated Video On Demand content are no longer available to Spectrum customers,” said the letter written by Shelley Winchenbach, director of government affairs for Charter Communications.

In recent years, TV station blackouts have become more common as pay-TV distributors, including Charter, struggle to rein in programming costs, and negotiations over programming deals become more contentious. In this case, Tribune Media has been demanding that Charter pay higher fees for the rights to retransmit the signals of 33 Tribune TV stations in Charter Spectrum markets.

The companies said negotiations are continuing.