HAWTHORNE, California: SpaceX has struck a deal to acquire a nationwide low-band spectrum portfolio, bringing Elon Musk's satellite company closer to competing directly with established U.S. wireless carriers through its Starlink Mobile service.

SpaceX will pay about US$8 billion in cash for the assets to private-equity firm Grain Management, the Wall Street Journal reported, citing people familiar with the matter. Financial terms of the agreement were not officially disclosed.

SpaceX and Grain did not immediately respond to a request for comment.

Starlink Mobile already has global 2 GHz mid-band spectrum for high-bandwidth capacity. The newly acquired low-band frequencies can travel long distances and penetrate dense structures such as walls and tree cover, addressing a major technical hurdle faced by satellite-based mobile networks.

By pairing nationwide low-band airwaves with high-frequency space capacity, SpaceX is positioning Starlink Mobile to bypass conventional cell towers and compete with established wireless carriers on coverage and in-building reliability.

Shares of T-Mobile US, Verizon and AT&T fell around 6% in extended trading. The three carriers formed a satellite-focused joint venture in May that some analysts believe is intended to respond to the threat from SpaceX.

"The incumbent wireless carriers have been vocal in expressing skepticism that SpaceX's network will be able to match the quality of their networks," William Blair analysts said.

"We expect SpaceX to offer a very compelling Starlink broadband and Starlink Mobile bundle. The company may also include Grok in the package," they added, referring to the AI chatbot developed by Musk's xAI.

The transaction involves acquiring 100 percent of Grain Management's nationwide 800 MHz spectrum portfolio and remains subject to Federal Communications Commission approval. Grain acquired the airwaves from T-Mobile earlier this year.

"We are going to see more investment, more opportunities for a range of providers, and America leading the world in next-gen technologies to the benefit of consumers all across the country," FCC Chair Brendan Carr said in response to the deal.

Grain CEO David Grain said the deal has "the potential to change where and how Americans connect."

Most existing mobile handsets support the 800 MHz frequency band, eliminating the need for consumers to purchase proprietary satellite phones.

Verizon spokesman Rich Young said hurdles remained. "This company can have tons of spectrum available, but if they do not have the network to use it, it doesn't matter. It's just empty airwaves," Young said.

The FCC also approved Starlink Mobile's Gen2 constellation application this week, authorizing SpaceX to launch 15,000 satellites optimized for 2 GHz spectrum globally. The satellites will operate in very low Earth orbit and are intended to deliver expanded bandwidth and low-latency connections to standard handsets.