The 4G mobile broadband spectrum auction will now not take place until early 2013, it has been announced.
Ofcom had been intending to distribute spectrum in the 800MHz and 2.6GHz frequency bands during the second half of 2012, but the regulator has pushed back its timescale.
This is because it needs additional time to assess the responses to its recent consultation on 4G mobile services.
Mobile broadband providers will be invited to submit applications at the end of 2012, but the actual bidding process will now take place in the new year.
Operators are expected to start rolling out 4G networks from the middle of 2013, and to start offering services later that year.
The latest announcement comes as something of a blow to mobile broadband users, who are looking forward to faster download speeds and improved coverage when 4G launches.
Ofcom wants to see super-fast mobile broadband coverage in 98 per cent of the UK following the launch of fourth-generation services.
And this means consumers should be able to use dongles and web-enabled mobile devices to access the mobile internet in more rural locations.
Everything Everywhere - the UK parent company of Orange and T-Mobile - Vodafone and O2 are sure to be among the bidders for 4G spectrum in the new year.
Three may also enter the race for 800MHz and 2.6GHz spectrum, along with the likes of Hutchinson 3G and potentially a new market entrant.
"In the interests of competition, Ofcom has decided to reserve a minimum amount of spectrum in the auction for a fourth operator," the regulator stated.
"Ofcom has concluded that UK consumers are likely to benefit from better services at lower prices if there are at least four credible national wholesalers of 4G mobile services."
Ed Richards, Chief Executive at the media regulator, said the 4G auction has been designed to deliver "the maximum possible benefit" to consumers and citizens across the UK.
"As a direct result of the measures Ofcom is introducing, consumers will be able to surf the web, stream videos and download email attachments on their mobile device from almost every home in the UK," he stated.