But even if AT&T were kept out of the bidding, the resulting capacity that smaller carriers might gain would do little to alter the competitive balance, he said. "At the end of the day, however the Verizon sell-off turns out, the gap between the biggest companies and the rest of the industry would grow and the competitive world would shrink even more. Consumers would again be the losers."

The Rural Cellular Association, a trade group, also weighed in with concerns about Verizon's proposed sell-off, echoing both the broadcasters' accusation of spectrum hoarding and the advocacy groups' warning about the anti-competitive implications of the cable deal.

"This announcement confirms what RCA has said: Verizon has developed a spectrum warehouse exceeding its needs," RCA President and CEO Steven Berry said in a statement.

"Selling its Lower 700 MHz A and B block licenses is not sufficient to resolve competitive concerns in the industry," Berry added. "Further, Verizon's announcement increases RCA's concerns with the pending cable transactions, including access to usable, LTE-ready spectrum and access to commercially reasonable roaming and backhaul arrangements. These deals require strict scrutiny, enforceable conditions helping to restore the competitive marketplace, and divestiture in markets where the transfers are not in the public interest."

Verizon, for its part, defended its resale proposal, touting the widely acknowledged value of the 700 MHz band.