The UK's top mobile operators have agreed to launch faster mobile services by Spring 2013.
After a meeting with Ofcom and Culture Secretary Maria Miller, operators said they would launch six months earlier than originally planned.
They will also drop planned legal action against EE, whose 4G network is set to launch this year after it was granted permission by the regulator to use existing spectrum for the service.
O2 and Vodafone were among the operators expected to challenge the decision.
But now they will drop the threat in return for a quicker release of the 4G spectrum after an auction planned for January 2013.
The next-generation of mobile broadband offers download speeds up to five times faster than 3G, and has already been available in other countries for several years.
The spectrum - which includes that used for terrestrial television - is expected to raise billions at auction.
Ed Richards, Ofcom chief executive, said: "The actions we have taken with industry and government avoid the risk of significant delay and are tremendous news for consumers who might otherwise have waited a considerable period for the next generation of mobile broadband services."
A spokesperson for Three mobile said: "We see this as positive step for UK consumers by removing the monopoly on LTE that would have benefitted just one operator."
EE has said that it will launch 4G is 16 cities by the end of 2012, once it gets the final go-ahead.
The company, which also operates Orange and T-Mobile, has been encouraging purchasers of the new 4G-enabled iPhone 5 to sign up via its current networks and then switch once EE's 4G plans become available.
Kester Mann, senior analyst at CSS Insight, said:
"The freeing up of spectrum for 4G some five months earlier than previously planned is positive news for Vodafone, O2 and 3 as they will now be in a position to launch in spring 2013. This is great news for the UK, as consumers will sooner be able to benefit from a more competitive market for 4G services.
"However, the agreement slashes EE’s first-mover advantage and means it will need to work much harder and be more aggressive in its roll-out and marketing if it’s going to capitalise on its period of exclusivity."