Google has disclosed for the first time that it is prepared to bid in a forthcoming auction of wireless spectrum in the US, a move that could eventually mean it will emerge as a fully fledged operator of a wireless communications network.

However, while the search company indicated it was prepared to bid at least $4.6bn, it said it would take part only if federal regulators adopted rules for the auction that had already been strongly opposed by existing wireless companies.

That condition, and early signs of the Federal Communications Commission’s position on the issue, made it far less likely that Google would step forward to bid, according to analysts.

The search company’s declaration of interest comes days before the FCC is due to set the rules for the most important auction of new wireless spectrum in the US in years. Known as the 700Mhz auction, it will release a large block of spectrum for new high-speed wireless networks previously used by TV broadcasters.

Kevin Martin, the FCC’s chairman, is understood to have already proposed rules that would go some way to meeting what Google and other internet and technology companies have been urging.

The winning bidder for part of the spectrum would be required to adopt “open access” provisions that would let customers use any handset and access any internet service over the network, without needing the approval of the operator – a form of “network neutrality” that echoes similar provisions internet companies have pushed for, so far without success, on wired networks.

In a letter to Mr Martin on Friday, Eric Schmidt, chief executive of Google, welcomed these provisions. However, he said that “the current draft order falls short of including” all the requirements for openness that Google believes should be attached to the new spectrum.

In particular, the internet company wants a requirement that would force the winning bidder to sell wholesale access to its network, based on what it called “nondiscriminatory commercial terms”. That would make it possible for other wireless companies to operate on the network, potentially increasing competition.

Google and other internet companies argue that the auction should be used to break the broadband duopoly that exists in the US between cable and fixed-line telephone companies.

Wireless companies, however, oppose the requirement to offer wholesale terms, claiming it would undermine the business model of the traditional wireless industry.

Steve Largent, head of the wireless industry trade group CTIA, accused Google of trying to have the auction ”rigged with special conditions in its favour”.

If the internet company were to win spectrum in the auction it would be free to adopt its openness principles, without requiring the govenment to force them on other bidders as well, he added.