Two of the world's largest mobile network operators are to join forces in a bid to speed up the delivery of super-fast 4G services to UK households.
Vodafone and O2-owner Telefonica will continue to compete but will pool their infrastructure to operate and manage a single network grid across the country.
The move will be seen as a challenge to Everything, Everywhere, which operates Orange and T-Mobile.
Everything, Everywhere is helping to run the 4G Britain campaign to hasten the switch to 4G - and is lobbying for Ofcom to allow its existing spectrum to provide the service ahead of an expected auction for 4G spectrum following its latest consultation.
O2 and Vodafone said the move will see 4G mobile services, which will allow users to download music and film to their phones at the same speeds as home or office computers, delivered up to two years ahead of Ofcom's requirement of 98% coverage by 2017.
The two companies won't share spectrum but will share a network of 18,500 mobile sites.
If the agreement is agreed by Ofcom the companies will form a joint century which could see up to 10% of existing mobile sites dismantled.
The idea, the companies say, is to build "one grid, two networks".
Ronan Dunne, CEO of O2 parent company Telefónica UK said: "Exceptional customer demand for the mobile internet has challenged the mobile industry to consider innovative solutions to building a nationwide network that will be fit for our customers in the future."
"This partnership is about working smarter as an industry, so that we can focus on what really matters to our customers."
Guy Laurence, Vodafone UK chief executive, said: "This partnership will close the digital divide for millions of people across the country and power the next phase of the smartphone revolution."