Source: Sharecast
Officials had been reviewing two proposals, one from Heathrow itself and another from Arora Group, which is led by hotel tycoon Surinder Arora.
The latter had proposed a shorter third runway, which would cost less and mean the M25 would not need re-routing.
However, on Tuesday the Department for Transport said Heathrow’s own proposal offered the "most deliverable" option. It also said it had the "greatest likelihood" of getting planning approval within the current parliament.
The plan will now inform the government’s review of the Airports National Policy Statement, which is the framework under which the planning decision will be made.
The department stressed that selecting Heathrow’s plan "did not represent a final decision on a third runway or design", noting that exact details - including the runway’s length, layout and any infrastructure implications - would continue to be reviewed.
However, transport secretary Heidi Alexander called the decision "another important step to enable a third runaway".
She continued: "Heathrow is our only hub airport, which supports trade, tourism and hundreds of thousands of jobs.
"We’re acting swiftly and decisively to get this project off the ground so we can realise its transformational potential for passengers, businesses and our economy sooner."
Heathrow has long wanted to expand, but has faced opposition from local groups, environmental campaigners and successive governments.
However, Rachel Reeves threw her weight behind expansion plans shortly after becoming chancellor, as part of plans to bolster long-term economic growth.
Once the review of the ANPS is completed, Heathrow will apply for planning permission, with a potential decision by 2029.
Heathrow plans to spend around £33bn on the third runway and around £15bn on upgrades to the existing airport, all of which it insists will be privately financed.