Wireless carrier Sprint is trying to merge with cable giant Charter Communications, The Wall Street Journal reported today.

Sprint Chairman Masayoshi Son proposed the merger to create "a new publicly traded entity that would combine Sprint and Charter and be controlled by Japan's SoftBank Group," the Journal wrote, citing "people familiar with the matter." Son is the founder and CEO of SoftBank, which owns Sprint.

One thing that isn't certain is whether Charter wants to merge with Sprint. "It is far from guaranteed that Charter would ultimately agree to such a deal," the report said.

(UPDATE: Bloomberg now reports that Charter isn't interested in a merger with Sprint. Charter has not commented publicly, however.)

Sprint is the fourth largest of the four nationwide wireless carriers in the US. Charter is the second biggest US cable company after Comcast.

Charter would need Comcast’s permission

Comcast could be an obstacle to any deal. Comcast and Charter in May announced an agreement to cooperate in their plans to sell mobile phone service. That agreement also forbids each company from making wireless mergers and acquisitions without the other's consent for one year.

Shortly after the two cable companies announced their agreement to work together, Comcast and Charter reportedly began negotiating with Sprint over ways the three companies could cooperate in offering wireless service. One possibility under consideration was for Comcast and Charter to invest in improving Sprint's network in exchange for better terms in a deal to resell Sprint data.

Comcast and Charter each have agreements with Verizon Wireless to resell that company's mobile service under their own brands. Comcast is already selling its wireless service and Charter plans to do so in 2018. Both are currently restricting wireless service to their cable territories, which means they would not compete against each other unless there's a major change—like a merger.

The Sprint/Charter merger reportedly proposed by Son would apparently not involve Comcast at all. But Charter would need Comcast's consent to make such a deal because of that cooperation agreement. If Charter were to buy Sprint, it would then have a nationwide wireless footprint—and compete against Comcast for wireless customers.

Because of the Comcast/Charter agreement to cooperate, they are exploring ways to create common operating platforms that could be used by both cable companies. Comcast and Charter also pledged to explore working together on "technical standards development and harmonization... and emerging wireless technology platforms."

Despite the Sprint/Charter talks, the Journal's sources suggested that T-Mobile USA could still merge with Sprint. "Even if Sprint and Charter did strike a merger or resale deal, it wouldn't preclude a subsequent tie-up between the new group and T-Mobile," the Journal wrote.

Charter and Sprint each declined to comment when contacted by Ars.

Disclosure: The Advance/Newhouse Partnership, which owns about 13 percent of Charter, is part of Advance Publications. Advance Publications owns Condé Nast, which owns Ars Technica.