The Federal Communications Commission (FCC) has taken steps to increase competition in the US cable set-top box industry.
The proposal could disrupt the $20bn (£14bn) set-top box market by allowing companies such as Apple and Alphabet to sell competing devices.
US cable customers rent the boxes at an average cost of $231 a year, on top of cable TV charges.
The proposal sparked criticism from the already struggling cable TV industry.
Growing competition from online TV subscription services such as Netflix and Hulu has been eroding cable companies' customer numnbers and profits.
The FCC has said opening the set-top box market to smart TV and tablets would lower the price for consumers. The proposal requires cable companies to give alternative providers access to cable programming.
It said that set-top box rental fees had risen by 185% since 1994.
Regulators voted 3-2 in favour of moving ahead with the proposal, which will now be opened to public consultation.
A set-top box translates the signals carried by cable providers into images and sound. Some third parties already have this technology, but need to make private deals with cable companies to gain access to programming.
The proposal sparked a wave of lobbying from both sides that forced the FCC to call off a Twitter "town hall" - open meeting - on Wednesday.
Bob Quinn, of AT&T, said: "While consumers are embracing an apps-based approach that offers a variety of content on more than 450 devices, the FCC has chosen to go down a path that threatens the very competition and innovation that has led to this vibrant marketplace."
Stanton Dodge, of Dish Network, said: "It is really not clear to us that any new regulation is needed to encourage innovation and in fact would actually hinder it."