By Thomas Gryta 

The Justice Department on Thursday warned the coming airwaves auction runs the risk of concentrating more wireless spectrum in the hands of AT&T Inc. and Verizon Communications Inc., the nation's two largest U.S. wireless carriers.

In a letter sent Wednesday, the Justice Department urged the Federal Communications Commission to consider helping smaller nationwide carriers gain access to valuable spectrum at a major airwaves auction next year.

One way to do that would be to increase the amount of airwaves set aside for smaller companies in the auction slated for early 2016, a position that has been pushed by smaller operators such as T-Mobile US Inc.

William Baer, assistant attorney general for the antitrust division, in the letter called on the FCC to consider "the well-established competition principle that those with market power may be willing to pay the most to reinforce a leading position."

A senior FCC official said Thursday that it wouldn't propose increasing the amount of spectrum earmarked for small operators, keeping with its suggested 30 megahertz reserve.

The auction will open up airwaves currently used by television broadcasters for wireless use. The frequencies, often referred to as low band, are considered to be very valuable because they are good at carrying signals over long distances and deep into buildings. The majority of low-band spectrum is currently held by AT&T and Verizon.

"The Commission should ensure that the allocation of spectrum through the auction does not enable carriers with high market shares to foreclose smaller carriers," Mr. Baer wrote in the letter.

AT&T and Verizon have about 75% of the mainstream customers that use the four major U.S. wireless carriers as of the end of March, according to UBS.

The letter shows the Justice Department retains concerns about the concentration of market power in the wireless industry. In April 2013, Mr. Baer pushed publicly for the FCC to govern spectrum holdings in a way that ensures smaller nationwide carriers can compete.

In recent years, the Justice Department has helped stop consolidation among the major carriers, including suing to block in AT&T's attempted $39 billion acquisition of T-Mobile. Last year, the Justice Department made it clear that it would likely oppose an attempted merger of T-Mobile and Sprint Corp.

On Wednesday, a group of Democratic senators also wrote to the FCC, saying it should "evaluate its auction rules to ensure they prevent excessive concentration of spectrum among the nation's largest wireless providers."

An AT&T spokesman declined to comment. The company has argued recently that T-Mobile is advocating for the rules to avoid competitive bidding in urban markets. AT&T has said its spectrum holdings in rural areas are insufficient so it would able to bid on all the spectrum on offer.

Verizon, meanwhile, said T-Mobile doesn't need any set asides in the auction. "T-Mobile is a well-funded entity that, along with its partner company, Deutsche Telekom, is more than financially capable of competing in a fully open auction," a Verizon spokesman said.

The FCC's proposed rules on how much spectrum be reserved for smaller operators will circulate among the commissioners for vote in July, though there is still an opportunity for revisions.

T-Mobile is holding out hope that the FCC's position will change. Andy Levin, T-Mobile's head of government affairs, said the Justice Department letter suggests there is still room to influence the process.

"There would be no point in writing the letter if they didn't want the FCC to take another look," Mr. Levin said.

Write to Thomas Gryta at thomas.gryta@wsj.com

Access Investor Kit for AT&T, Inc.

Visit http://www.companyspotlight.com/partner?cp_code=P479&isin=US00206R1023

Access Investor Kit for Verizon Communications, Inc.

Visit http://www.companyspotlight.com/partner?cp_code=P479&isin=US92343V1044

Subscribe to WSJ: http://online.wsj.com?mod=djnwires

Verizon Communications (NYSE:VZ)
Historical Stock Chart
From Mar 2024 to Apr 2024 Click Here for more Verizon Communications Charts.
Verizon Communications (NYSE:VZ)
Historical Stock Chart
From Apr 2023 to Apr 2024 Click Here for more Verizon Communications Charts.