Comcast Corp. and Charter Communications Inc. have struck a wireless partnership as the cable giants look to get a piece of the cutthroat business.

As part of the deal, which The Wall Street Journal first reported Sunday, Comcast and Charter have agreed not to make a material merger or acquisition in wireless without the other’s consent for one year.

That agreement could stoke Wall Street speculation among investors and analysts that the two largest U.S. cable companies together could decide to make a play for a carrier like T-Mobile US Inc. or Sprint Corp. Neither company as a single entity could buy another wireless carrier for that time period as a result of that agreement without the other’s blessing or involvement.

Wireless carriers are fighting it out in a fierce price war, while cable companies like Comcast and Charter are dealing with a saturated pay-TV business under assault from threats like cord-cutting and cheaper online video services.

The cable companies view wireless phone service as an opportunity to create a new product to make their bundles more appealing and better retain existing customers. They hope that by offering a “quad play” of cable TV, home internet, landline phone and wireless service, customers will be less likely to drop their service and jump to a rival.