Warren sounds alarm on T-Mobile, U.S. Cellular deal with Justice Department, FCC

• Six senators are asking the Justice Department and the Federal Communications Commission to consider challenging a deal that would allow T-Mobile to use part U.S. Cellular's wireless spectrum.
• New letter from lawmakers says consumers could be charged billions more from higher-priced carriers with lower-prices carriers combining.
• Lawmakers also ask the Justice Department to consider unwinding the merger of T-Mobile and Sprint.

WASHINGTON — A group of Democratic senators are sounding the alarm over T-Mobile's proposal to acquire most of US Cellular, and asking the Justice Department and the Federal Communications Commission to closely scrutinize and consider challenging the deal.

The $4.4 billion deal announced in May 2024 would allow T-Mobile to use part U.S. Cellular's wireless spectrum to improve its coverage in rural areas and give it access to four million new customers. In the letter, six Democrats wrote. that the plan would raise costs for customers and limit choices.

"Additional consolidation in the market would have far-reaching effects, reducing choices for consumers, further concentrating wireless spectrum holdings, and potentially leading to higher prices and other harms for consumers across the country," the senators wrote in the letter, obtained exclusively by CNBC.

The letter was led by Sens. Elizabeth Warren (Mass.) and Amy Klobuchar (Minn.), with Sens. Chris Murphy (Conn.), Bernie Sanders (Vt.), Cory Booker (D-N.J.), and Richard Blumenthal (Conn.) co-signing.

Under the agreement, U.S. Cellular would retain 70% of its wireless spectrum and towers, leasing space on other towers to T-Mobile.

Warren and Klobuchar have previously raised concerns about T-Mobile's acquisitions and merger with Sprint.

In Monday's