Heathrow further pushed its case for a third runway by reporting high demand in the first half of the year.
Passenger numbers increased by 1.3% to 35.5 million in the six months to June 30 over the same period in 2014.
Half year pre-tax profits were up to £120 million from £23 million a year earlier based on revenue rising to £1.3 billion from £1.23 billion.
Heathrow has been backed by the Airports Commission for expansion with a decision due from government before the end of the year.
The London hub revealed that its expansion proposal is expected to involve privately funded investment of £16 billion.
“Heathrow intends to fund the expansion through its established and scalable financing platform and expects to target its existing investment grade credit rating,” the airport said.
“The major funding requirement is not expected until planning consent is obtained, which is expected by 2020, with the new runway operational from 2025.
“The government will now take time to review the [Airports Commission] report to make a policy decision which is expected by the end of the year.
“Heathrow will engage with government on the options to progress expansion through this period and will work with communities, airlines and all stakeholders to build on the Airports Commission’s clear recommendation for Heathrow’s expansion.”
Heathrow’s chief executive, John Holland-Kaye, said: “Heathrow’s performance in the last six months has been excellent, improving service to passengers and controlling costs.
“The Airports Commission’s unanimous and clear recommendation to support Heathrow was warmly welcomed by business leaders and politicians from across the country and closed the debate on where a new runway should be built.
“Our focus now is on working closely with government to deliver the benefits of expansion for all of the UK as quickly as possible.”
Heathrow reported a 2.4% rise in European traffic in the first half was largely driven by British Airways raising short haul capacity.
Long haul travel was up by 0.4% helped by increased use of the Airbus A380 superjumbo which accounts for 20 daily arrivals and departures by eight airlines.
But traffic on Asia Pacific routes declined slightly, partly reflecting the impact of competition from other international hubs, Heathrow said.
A total of £280 million was spent on airport improvements in the six months as part of a £700 million capital expenditure plan for 2015.