Three has acquired key chunks of Everything Everywhere's 1800MHz spectrum, allowing it to pave the way for the introduction of 4G services on its network.
The UK mobile operators confirmed the sale, which will see two 15MHz blocks of spectrum in the 1800MHz band allocated to Three. The financial terms of the deal were not disclosed in the announcement on Tuesday.
The acquisition is important for Three, the smallest of the major UK operators, as it allows the company to start laying the groundwork for rolling out 4G LTE services.
However, it is unclear when Three will be able to launch those services, as the timing depends on when Everything Everywhere will stop using the blocks of spectrum and on getting the go-ahead from the European Commission.
On Monday, Ofcom announced its decision to liberalise the 1800MHz band, which opened the door for Everything Everywhere to begin providing 4G services on that band as soon as 11 September.
That means the company, which runs T-Mobile and Orange, can get going ahead of the UK's auction of 800MHz and 2.6GHz spectrum for 4G services, expected at the end of 2012.
However, though Three now also has a presence in the 1800MHz band via the two 15MHz blocks it has acquired, it needs Everything Everywhere to fully vacate the two chunks before it can start preparing the infrastructure for 4G services. Under the deal, the seller is not obliged to do that until September 2013.
If Everything Everywhere gives permission for Three to take over before that date, then Three could introduce its competing 4G services just a few months after Everything Everywhere's launch. Otherwise, Three's 4G debut is likely to come towards the end of 2013.
With the deal, Everything Everywhere is complying with a stipulation in its merger agreement with Ofcom and the European Commission. When it formed, Everything Everywhere was required to divest portions of its 1800MHz spectrum to another operator, as it owned so much spectrum in the band.
Three successfully secured the spectrum after a sealed bidding process that included other operators, ZDNet understands.
The spectrum sell-off will now go in front of the regulators to see if it fulfils Everything Everywhere's obligations.
"Ofcom and the European Commission will review whether the divestment satisfies the merger commitments, and a response is expected within the next three months," the company said.