Profits at Heathrow and Stansted rose nearly 10% to €1.15 billion - before tax - in the first three quarters of 2012.
Passenger numbers at Heathrow rose slightly by 0.6% to 53 million, while traffic at the two airports combined dipped 0.5% to 66.4 million.
Heathrow Ltd – the new name for BAA – said its “strong operational performance” during the Olympics drove passenger satisfaction to “record levels”.
Colin Matthews, CEO of Heathrow, said €1.25 billion of investment was helping create jobs in the UK and improving the passenger experience.
He added: “Heathrow continues to report a strong operating and financial performance.
“It received its highest ever passenger satisfaction scores during a period which included the London 2012 Olympic and Paralympic Games.
“Our large and sustained capital investment programme is creating jobs throughout the UK and improving passengers’ experience of Heathrow.
“We are on track to invest more than €1.25 billion by the end of 2012, with the next major milestone being the opening of the new Terminal 2 in 2014.”
The company’s Q1-3 financial report also noted that the “disposal of Stansted” was underway.
Manchester Airports Group (MAG) has confirmed it is bidding for the airport, while other rumoured interested parties include Macquarie, Cheung Kong Holdings and infrastructure investor Morrison & Co.
Heathrow Ltd announced it would sell Stansted in August, following a lengthy legal battle to hold onto the airport.
The UK Competition Commission ruled BAA should sell three of its seven airports in 2009.
It completed the sale of Edinburgh Airport to Global Infrastructure Partners (GIP) in April this year. GIP bought Gatwick Airport in December 2009.
The UK Court of Appeal rejected BAA’s appeal against the sale of Stansted in July 2012, and the following month, BAA said it was giving up its fight to keep the airport.