"Today's proposal by Verizon to sell reallocated broadcast TV spectrum involves airwaves in the largest urban markets in America that it purchased more than four years ago," Dennis Wharton, executive vice president of communications for the National Association of Broadcasters, said in a statement. "The fact that it has warehoused this 'beachfront property' raises the fundamental question of whether a spectrum shortage actually exists."

Wharton's group has been a consistent critic of the wireless industry's efforts to press policymakers to shift spectrum from television broadcasters to the carriers, and has fought against any proposal that would pressure its members to give up their licenses. Earlier this year, Congress passed legislation authorizing the FCC to conduct auctions to resell broadcast licenses to wireless providers, giving the TV stations that participated a portion of the revenues, but the NAB won significant safeguards to ensure favorable operating conditions for broadcasters that remain on the air.

Verizon's latest spectrum proposal has also drawn criticism from groups that broadly support freeing up more spectrum for wireless broadband, but oppose the carrier's deal with the cable companies and generally warn against consolidation and anti-competitiveness in the mobile and broadband Internet sectors.

"There is less than meets the eye to Verizon's spectrum sale. At the end of the day, Verizon and the cable companies will still have created a cartel in which Verizon will rule the air for wireless broadband and cable will offer the only widespread true high-speed landline Internet services," said Harold Feld, legal director for the consumer advocacy group Public Knowledge.

"Verizon is trying to use the mere offer of a spectrum sale tempt the FCC and the Justice Department into approving the deal with the cable companies, and the agencies should resist the temptation," Feld added, suggesting that AT&T, Verizon's biggest rival, would be a likely buyer.