The high bids totalled $3.2bn in the US Federal Communications Commission's auction of wireless spectrum licences in the 700MHz band after three rounds and a day and a half of bidding.

That figure is far short of the $10bn Congress and the FCC expect to raise in the auction, which opened Thursday, but bidding could continue for weeks. In most cases, the high bids don't yet meet the FCC's reserve price set for minimum winning bids.

A fourth round of bidding will take place on Friday afternoon.

The 700MHz auctions represent the last large chunk of spectrum available for the FCC to auction in the foreseeable future. The spectrum, now used to carry over-the-air television signals, can be used for long-range wireless broadband traffic. Consumer groups have said the spectrum represents the "last, best hope" for a nationwide wireless broadband network that competes with cable and telecom broadband services.

For sale is 62MHz of spectrum in the 700MHz band. In late 2005, after a decade of debate, Congress passed a law requiring US TV stations to move to all-digital broadcasts and abandon the analog spectrum between channels 52 and 69. The deadline for TV stations to end broadcasts in the 700MHz band is February 2009.

After three rounds, 906 of the 1,099 available spectrum licences had bids, with four more licences receiving bids than at the end of round two late Thursday. High bids had totalled just under $2.8bn after round 2, and just over $2.4bn after round one Thursday morning.

Top bid

The top bid after the third round was $1.49bn for eight of 12 regional licences in the C block, a 22MHz block of spectrum covering all 50 states. The bidding for those C block licences was up from $1.24bn at the end of the second round. The FCC's reserve price for the C block is $4.6bn, and the winning bidders of C block spectrum must allow any legal devices to connect to their network, including mobile phones purchased from other carriers.

The second highest bid remained $472m for the D block, a nationwide 10MHz chunk of spectrum to be paired with another 10MHz set aside for public safety agencies. The bidder of the D block would be required to build a national network to be jointly used by public safety agencies and commercial customers. The high bid for the D block has remained unchanged since round one. Bidding in the auction is anonymous.

The A block, a 12MHz piece of spectrum covering parts of New York and the northeastern US, also generated interest. The high bid was $119.8m after the third round, up from $100m after the second round and $83.2m after the first round. A similar chunk of spectrum in the E block, also covering the same area, has generated a high bid of $59.9m after the third round.

The high bid for a 12MHz block called the B block, for a local New York City license, stood at $85.6m after rounds two and three.

High bids for five blocks in the Chicago, Los Angeles and Washington, DC, areas were between $28m and $55m after round three.