Heathrow traffic increased 2.4% to 34.4 million passengers in the first half of the year.
The increase helped the airport move into the black with a pre-tax profit of £186 million in the six months to June 30 against a loss of £51 million in the same period the previous year.
Heathrow warned that the lead times to implement any recommendations from the government’s Airports Commission in terms of new runways are expected to be “significant” even if immediate political consensus in support of the recommendations is achieved.
The airport has put forward options for a third runway costing up to £17 billion to increase capacity to 740,000 flights and 130 million passengers a year
The Commission is expected to produce an interim report by the end of the year and to report its full findings in summer 2015.
Heathrow reiterated its “disappointment” over proposals from the Civil Aviation Authority over economic regulation from April 2014.
It said: “Heathrow believes the CAA initial proposals materially underestimate Heathrow’s cost of capital and propose unrealistic cost reduction targets, the result of which is a failure to adequately incentivise investment to the detriment of passenger experience.”
The airport last week put forward an alternative business plan which it said was conditional on “fair and reasonable” final proposals from the CAA, due for publication in October.
Heathrow chief executive Colin Matthews said: “Performance at Heathrow this year is encouraging.
“The number of passengers using the airport increased, passenger satisfaction hit record levels and we maintained solid delivery of our service standards.
“Our earnings support the investment made in Heathrow and that continues with the new Terminal 2: The Queen’s Terminal opening in June next year.
“We want to build on our achievements and continue that progress over the next five years, which is why we’ve submitted fresh plans to the CAA for a further £3 billion of investment, if returns to investors are fair and competitive.”