SpaceX reached a deal to buy cellular spectrum licenses from investment firm Grain Management, its biggest move yet into a wireless market dominated by traditional telecom companies.

The U.S. licenses, which sit around 800 megahertz, are tailored for wireless service from cellphone towers rather than satellites. The spectrum could serve SpaceX's stated ambition of moving its Starlink satellite service beyond broadband into the wireless market to compete with the likes of AT&T and Verizon.

SpaceX said that once it receives approval from the Federal Communications Commission, it will deploy Starlink Mobile to combine its satellite-to-mobile constellation with a terrestrial network to connect devices.

SpaceX made an early commitment to the wireless market last year with a roughly $17 billion cash-and-stock deal for satellite-based spectrum rights from EchoStar. The purchase gave Musk's company a platform for beaming data to cellphones from space using its own reserved frequencies rather than through airwaves licensed from partner T-Mobile.

EchoStar later agreed to sell some ground-based cellular licenses to SpaceX for $2.6 billion. The purchase hinted at SpaceX's budding interest in wireless service, though the spectrum alone wasn't enough to launch a full-fledged cellphone network without more airwave rights and access to the cell-tower equipment needed to use them.

AT&T, Verizon and T-Mobile earlier this year teamed up to extend their service to remote areas over satellite links, a move widely viewed as a defensive tactic against potential SpaceX encroachment.