The Federal Communications Commission said Wednesday it acquired $86.4 billion worth of wireless airwaves from television broadcasters in the first phase of a complex auction, an effort designed to free up TV spectrum for cellular use.

The agency hopes wireless carriers, cable companies and other bidders will be willing to spend that much when it resells the airwaves in an auction that will start later this summer.

But $86.4 billion is a staggering figure—it is more than the market cap of T-Mobile US Inc. and Sprint Corp. combined—and it is unlikely operators will actually pay that amount. If they don't, the FCC will reduce the quantity of airwaves it buys and ask broadcasters to accept a lower price. Then, it will return to carriers and auction off the smaller amount.

An FCC official said that is how the process was designed to work. The agency expects to have multiple rounds that will eventually match the supply with the demand.

"Strong participation from broadcast stations made this initial clearing target possible," said Gary Epstein, chair of the FCC's incentive auction task force. "Now the action shifts to the forward auction, which will give wireless bidders the opportunity to compete for this beachfront spectrum to meet America's growing mobile data needs."

Write to Ryan Knutson at ryan.knutson@wsj.com

(END) Dow Jones Newswires

June 29, 2016 12:45 ET (16:45 GMT)